Always Mobile

Always Mobile

Edm: 780-448-9243

Cal: 403-770-5625

Edm: 17812 118 Ave.

Edm: 5738 75 St.

Cal: 2020 32 Ave. NE

Exit Control Glossary of Terms

Courtesy of Detex




Radio transmission operating at 125 thousand cycles per second. This technology has historically been the standard for proximity cards/readers

128 Bit AES

A specification for the encryption of electronic data using a 128 bit symmetric key algorithm


Radio transmission operating at 13.56 million cycles per second. This technology has historically been the standard for smart cards/readers

161 Prep

Cutout (or hole) in a door for bored/cylindrical locksets. Also known as Cylindrical Lock Prep

26 Bit Format

The most common data format for RFID badges. It consists of 4 components. Even Parity (1 Bit), Facility Code (8 Bits), Card # (16 Bits) and Odd Parity (1 Bit)


Triple DES is a specification for the encryption of electronic data which applies the data encryption standard three times to each block

86 Edge Prep

See mortise lock prep


A–Go to Top

Access Control

Controlling entry of people into buildings, rooms, and racks, and controlling the use of keyboards and equipment, by the use of automated devices that either read information stored on an object such a card (what you have), receive a code or password (what you know), or recognize a physical trait by biometric analysis (what you are)

Access Credential

A medium that contains encoded information, such as ID cards, key fobs, & smart chips

Access Devices

Electronic and/or mechanical products developed to control entry and/or egress. Access devices can be single technology or a combination of technologies including card and keypad or card and code

Access Hole

Hole in outer body of the lock mechanism providing entree to the lock retrainer

Access Level

A logical group of doors paired with a time schedule used to determine when and where a card is granted access

Access Point

A place along the perimeter of a secure area where there is a door/gate/portal and some type of access control method to screen users attempting entry to the area

Active Case

Case of panic device which contains the latching mechanism

Active Detector

A sensing device which functions by transmitting energy. There are several types of active detectors including microwave, photoelectric, infrared, and ultrasonic

Active Door (in a pair of doors)

The leaf that opens first and the one to which the lock is applied

Actuating Bar

The activating mechanism of an exit device is located on the egress side of a door and extends at least half the width of the door. The active surface of the actuating bar shall be visually and physically distinct from the rest of the device. AKA cross bar or pushpad


Mechanism of a switch that operates the contacts. An actuator can be a door release

Actuator arm

Lever connecting the directional switch to the directional lever on some cars equipped with a dimmer switch on the steering column


Americans with Disabilities Act

ADA Requirements

The Federal “Americans with Disabilities Act” requires that buildings be accessible and contains specific requirements for doors

Adjustable Latch / Bolt

Latch/bolt mechanism for cylindrical locks that can fit either a 2-3/8" backset or a 2-3/4" backset

Adjustable Mortise Cylinder

A mortise cylinder whose length can be changed to fit the installation

Adjustment / Repair

Any action that could affect the outcome of a test conducted during an AAADM inspection


Indicates that the individual so identified is a qualified Architectural Hardware Consultant and member of the Door and Hardware Institute


Authorities having Jurisdiction

Alarm Condition

When an alarm system detects and signals that something has occurred such as an intrusion, a fire or hold-up

Alarm input

A monitoring point on a panel that checks the status of a device, typically digital (open/closed). Through the use of resistors, they may also monitor a normal/alarm/short/open

Alarm System

A combination of devices that detect and react to any abnormal condition

Allen Wrench

See Hex Key

All-Glass Slider

A sliding door package including a heavy glass panel that has no vertical stiles


See Associated Locksmiths of America

Alternating Current

An electric current that reverses its direction regularly and continually. The voltage alternates its polarity and direction of current flow negative to positive. AC current increases to a peak, decreases through zero and peaks in the opposite direction. AC current flows back and forth in the conductor and is expressed in cycles per second or Hertz (Hz)

Ambient Temperature

The temperature of the air in the immediately surrounding environment

Americans With Disabilities Act

An act passed to ensure the rights of the physically disabled. This act in part requires building to provide easier access for the physically impaired. Also known as ADA

Ampere (A, amp)

The unit of measurement for the rate of electrical current flow, characterized by the symbols 'I' (in Ohm's law formulas) or 'A.' One ampere is the current flowing through one ohm of resistance at one volt potential

Ampere/hour (AH)

A measurement of a battery's capacity. One ampere of current flowing for one hour equals one ampere/hour


A device used to attach a door frame to the surrounding structure or wall

Angle Bar

1. In a combination lock, a pivoting bar, which has the fence at its free end. 2. In a certain type of door lock, a steel bar which locks one end in the lock case, and the other end in a metal plate in the floor

Angle Bar Door Lock

A lock which mounts on the inside of an inswinging door, having a steel bar set at an angle, to connect the lock case with a metal plate on the floor

Angle of Cut

Cuts made at an angle other than perpendicular across the key blade. These include any offset angle


An audible and/or visual signaling device

Annunciator Vault Lock

A type of lock, made to be used on a vault's inner gate. An annunciator vault lock is designed to give a signal (for example ringing of a bell) every time the lock is opened


Production by electrical means of corrosion resistant film of oxide on the surface of aluminum and its alloys. Anodizing can be accomplished in a variety of different colors


The American National Standards Institute (ANSI) is a private, non-profit organization that administers and coordinates the U.S. voluntary standardization and conformity assessment system

ANSI Cut-Out

A standardized cut-out furnished on many rated and non-rated doors and frames


The process built into an RFID system that protects multiple cards from being read at the same time when within the readers RF field

Anti-Drill Ball Bearings

Ball bearings used to protect the shear line of a cylinder lock or placed in front of a combination lock's drill points. The purpose is to resist unauthorized entry

Anti-Drill Lunes

Small, hardened pieces of metal, shaped like a crescent moon. They can be installed into the housing of a lock cylinder to resist drilling. Their purpose is to resist unauthorized entry

Anti-Drill Rods

Small, hardened metal rods used to protect the shear line of a cylinder lock or placed in front of a combination lock's drill points. These variable shapes and sizes of anti-drill rods are designed to resist unauthorized entry

Anti-Dust Plate

See Dust Cover

Anti-Friction Latch

A device incorporated into a latch bolt to reduce the closing pressure required

Anti-Friction Bearing

Any bearing having the capability of effectively reducing friction

Anti-Friction Latch Bolt

A latch bolt designed to reduce friction when the bolt starts to engage the lock strike

Anti-Liftout Pin

See Door Edge Pin

Anti-Masking Circuit

An anti-masking circuit identifies any attempt to cover or obstruct the operation of certain infrared sensors


Refers to a systems ability to track an individuals in/out status at a facility, typically through entrance and exit card readers. Once a person has entered, they cannot enter again until they have exited

Anti-Tamper Switch

A normally-closed switch mounted into the cover of an electronic component. The switch is opened if the cover is removed, signalling unauthorized access. See also Tamper Switch


Products designed to prevent theft


Specially shaped padlock body with raised shoulders that covers the front and sides of the shackle


Application Programming Interface is a source code interface that is provided in order to support requests to be made by other computer programs and/or allow data to be exchanged

Approach Mat

A control mat that causes the door to open when activated


The side from which a person activates an automatic door

Architectural Hardware

Term applied to all hardware used in building construction but particularly that used on or in connection with doors, windows, cabinets and other movable members


The condition of an alarm system when it has been turned on

Armor Plate

A plate similar to a kick plate but covering the door to a greater height, usually 40" (1040 mm) or more from the bottom

Armor Plate Hasp

A hasp manufactured from case hardened alloy steel

Armored Face

A mortise lock that has a metal plate on the door edge. The armored face covers the lock cylinder set screws. The cylinder set screws are protected and cannot be loosened without first removing the armored Face. See also Armored Front

Armored Front

A lock that consists of two plates: one, the under plate, is fastened to the case and is unfinished; two, the finish plate, is fastened to the under plate and when in place covers the cylinder set screws thus protecting them from tampering. Used on mortise locks. See also Armored Face

Associated Locksmiths of America

The national trade association for retail, commercial, and institutional locksmiths


A molding or strip whose purpose is to cover or close the gap between the edges of a pair of doors. Some types overlap, others meet at the center line of the gap. See Coordinator

Attaching Screws

Screws used to fasten a lock and/or locking mechanism to the door

Attendant's Key

Single key used in mental institutions to operate patient room locks in various buildings and possibly under different master keys. This special key eliminates cross keying, but must be set-up at inception of the master key system

Audit Trail

A record of transactions that can be used by an interested party to trace an access control activities during a specific time period

Automatic Door

The combination of door, operator, and controls constituting the system

Automatic Extension Flush Bolt

A flush mounted locking device for the inactive leaf of a pair of doors. When the active leaf is opened, the inactive leaf is capable of being pushed open and when it closes, the bolt latches automatically by the closing of the active leaf and is held latched by the active leaf

Automatic Key Machine

Duplicates cylindrical keys automatically once the key and the key blank are positioned in the vises. Some automatic key machines brush the duplicated key after it is cut

Automatic Latching Two Point Bolts

A surface or concealed mounted top and bottom locking device for the inactive leaf of a pair of doors. It is manually unlocked to open, but when the leaf is closed, the bolts latch automatically

Auto Re-Arm

Alarm sounds if the door is opened in the armed condition, and will automatically re-arm 2 minutes after the door is closed

Auxiliary Dead Latch

A supplementary latch that automatically deadlocks the main latch bolt when the door is closed. Also called Deadlocking Latch Bolt

Auxiliary Latch

A separate secondary latch which is depressed by the strike when the door is closed. The auxiliary latch deadlocks the latch bolt. See also Auxiliary Dead Latch

Auxiliary Lock

Any secondary lock installed onto a door

Availability Percentage

A calculated prediction of a system’s percentage of “uptime.” For mission-critical facilities, the goal is “five "nines” or 99.999% - less than 5 minutes of downtime per year

B–Go to Top

Back Check

Optional feature in hydraulic door closers slowing the opening swing of door somewhere between 60 and 85 degrees of opening. Designed to protect an object be hind the door. Not intended to act as an overhead stop

Back Plate

A flat or nearly flat piece of metal, usually having three holes. Two of the holes are for mounting screws and the third hole is for the tail piece to extend into the locking mechanism

Back-Up Power Supply

Source of power which will operate the alarm and/or access control system should the primary power source stop. Back-up power supplies can either be battery or generator, depending upon site requirements and the law

Backset (of a hinge)

The distance from the edge of the door to the hinge

Backset (of a lock)

The horizontal distance from the face of the lock to the center line of knob hub, keyhole or cylinder (Measured from the high side of a beveled door)

Ball Bearing

A solid metal sphere. There are a number of functions for ball bearings in locks and locking mechanisms. Some examples are 1. ball bearings are used to increase drill resistance at critical points to stop entry. 2. Used as a tumbler in pin stacks. 3. Embedded into the key of a specific lock manufacturer this "floating" ball bearing operates two blocking pins

Ball-Bearing Hinge

A hinge equipped with ball bearings between the hinge knuckles to reduce friction (See Anti-Friction Bearing)

Ball Bearing Pin Tumbler

A type of tumbler pin which is flat on both ends, and is placed in a pin chamber above a ball bearing. The ball bearing makes contact with the key. The purpose of using this design is to cut down on the amount of wear caused by repeated insertion and removal of the key

Ball Catch

A push and pull fastening with a mortised case designed to hold the door in the closed position. Also known as a friction catch

Ball Detent

A spring loaded steel ball which enters into a caviry in the bolt of a combination lock when the bolt is fully extended. The ball detent acts to proper position the extended bolt


The amount of data a network can transport in a given time period

Bar Code

An access control option printed onto cards that uses a series of vertical lines of various weights and positions. Some of the bar code symbologies are Code 11, Code 39, Code 93, UPC/EAN and Codebar

Bar-code Card

A type of access control card that uses an array of machine readable bars and spaces to represent the encoded information such as card number

Bar Code Reader

A reader designed to scan bar codes in order to grant or deny access


The part of the tubular lock which surrounds the plug, inner bushing and sleeve(s)

Barrel Bolt

A type of bolt, usually of the surface-mounted kind, which has a circular cross section

Barrel Key

A key with a bit projecting from a round, hollow shank designed to fit onto a post and rotates in the keyway of the lock. Barrel keys are identified by dimensions of the neck, bit height, bit width, bit thickness and by the inner diameter (I/D) and the outer diameter (O/D) of the barrel

Barium Ferrite Card

A type of access control card that uses a pattern of magnetic spots to store information; read by laying flat on a reader. Also called a "magnetic spot card."

Base Anchor

A piece of metal attached to base of a door frame, to secure frame to the floor. Also known as Floor Anchor


A direct current (DC) electrical storage container. Batteries are available in a variety of amperate and voltages. Batteries are a power source and as a back-up power source for access control and alarm systems. Types of batteries include alkaline, dry cell, gel, lead calcium, lithium and sealed lead acid


A flat metal plate used to convert movement from vertical to horizontal and vice versa

Bell Key

A type of key whose cuts are in the shape of a wavy slot milled into the sides of key blade. These wavy slots usually run the entire length of the blade


One of the metallic elements used in certain card operated access control systems

Bevel (of a door)

The angle of the lock edge in relation to the face of the lock stile. Standard bevel is 1/8" in 2" (3.2 mm in 50.8 mm). If otherwise detailed it must be so noted in ordering locks

Beveled Door Edge

The edge of a door which is not at a 90 degree angle to the face of the door - standard bevel is 1/8 inch in 2 inches - narrow side of door is in contact with stop of frame when door is closed

Bevel (of a lock front)

The angle of a lock front when not at right angle to the lock case, allowing the front to be applied flush with the edge of a beveled door

Bevel (of a lock)

A term used to indicate the direction in which the latch bolt is in dined: regular bevel for doors opening in, reverse bevel for doors opening out


See Builders Hardware Manufacturers Association

BHMA Functions

01: Exit only, no trim or blank escutcheon 02: Entrance by trim when actuating bar is locked down 03: Entrance by trim when latch bolt is released by key. Key removable only when locked 04: Entrance by trim when latch bolt is released by key or set in a retracted position by key 05: Entrance by thumb piece. Key locks or unlocks by thumb piece 06: Entrance by thumb piece only when released by key. Key removable only when locked 07: Entrance by thumb piece. Inside or outside key locks or unlocks thumb piece. Outside key releases latch 08: Entrance by knob or lever. Key locks or unlocks knob or lever 09: Entrance by knob or lever only when released by key. Key removable only when locked 10: Entrance by knob or lever. Inside or outside key locks or unlocks knob or lever. Outside key releases latch 11: Entrance by control turnpiece. Key locks or unlocks control 12: Entrance by control turnpiece only when released by turning key. Key removable only when locked 13: Entrance by key or combination lock 14: Entrance by trim when latch bolt is released by knob or lever. Always active, no cylinder 15: Entrance by trim when latch is released by thumb piece. Thumb piece always active, no cylinder 16: Entrance by trim when latch is released by control turnpiece. Turnpiece always active, no cylinder 17: Entrance by control turnpiece. Inside or outside key locks or unlocks turnpiece. Outside key releases latch


The portion of a cylinder housing which contains the pin chambers. The bible is easily seen on the key-in-knob cylinders

Bi-Centric Cylinder

A lock cylinder, usually of the pin tumbler type, that has two plugs and two sets of pin chambers instead of one

Bi-Directional Key

For a one way lock cylinder, a key that will both extend and retract the dead bolt of the lock in which the cylidner is being used. Bi-directional keys are used to control access and egress between two or more key holders

Biometric Lock

A lock that is controlled by a biometric scanner, such as fingerprint, hand geometry, retina identification, etc.

Biometric System

A method of high security access control using a unique feature of the individual. For example, fingerprints, voice prints, or blood vessel pattern in the retina of an eye


Establishing personal identity verification using technology to measure a physical or behavioral trait - for example, a fingerprint

Bit (of a key)

The projecting blade, cut in a manner that actuates the tumblers and permits the lock bolts to be operated


The plate that is mounted onto the post of bit and barrel keys

Bit Height

The dimension of the bit from the post out

Bit Key

A key with a bit projecting from a shank. Similar to the base of the warded and/or lever lock. These keys are identified by the dimensions of the post, neck and height, width and bit thickness

Bit Key Duplicating Machine

A key machine with rotatable vise jaws capable of making cuts on the three edges of the key's bit. A slotting type cutter is used to make the cuts

Bit Key Lock

Type of lock, usually mortise style which is operated using a bit key

Bit of a Key

That part of a key which is inserted into a lock which is cut and/or milled to operate the lock

Bit Thickness

The dimension of the bit from side to side

Bit Width

The dimension of the bit from the neck forward


The pattern of a cut or cuts in a key blade which is used to align tumblers to a shear line

Bitting Area

The portion of the key blade into which the cuts are made


The part of the key which contains the distinctive pattern of cuts


1. An uncut or the unfinished key as it comes from the manufacturer. 2. A key before any cuts have been made on it. See also Key Blank

Blind Bolt

A type of bolt lock that can be operated only from one side of a door, and has no visible parts on the other surface of the door

Blind Code

1. Term used for any code number which is not a direct digit code. 2. Name assigned to an unused key combination for future reference

Blind Code Card

A plastic card supplied by a manufacturer of locks and cylinders, which personalizes the code to the signer

Blind Hole Construction Master Key System

A master key system in which the construction master key is voided by inserting one of the permanent keys into the key slot, and turning the plug. When this is done, the part or parts that had allowed the construction master key to operate are forced into a blind hole in the plug and thus cease to function

Blocking Diode

An electronic device used to allow electricity to flow in only one direction

Blocking Ring

A ring the same diameter as the cylinder face, used to cover the exposed portion of a mortise cylinder


Building Officials and Code Administration international


The part of a lock which moves across the opening and stops the door, drawer, etc., from moving. This can be accomplished either mechanically or electrically. Bolts can be operated by the proper key, combination, code, card, hand, etc.

Bolt (Flush)

A vertical locking bolt so designed that when installed within the door, it is flush with the edge of the door

Bolt (Mortised)

A locking bolt installed within a door

Bolt (Surface)

A locking bolt installed on the surface of a door

Bolt Types

Combination lock safe bolts secure the door from being opened. They retract when proper combination is dialed and the locking mechanism is retracted. There are five basic types of these bolts. They are: Square Bolt, Center Extension Bolt, Upper Extension Bolt, Lower Extension Bolt, and a Roller Bolt

Bond Box

The removable sheet metal box inserted into the safe deposit box


A type of liability insurance designed to protect the locksmith when performing certain services

Bond Sensor

A Hall Effect or Reed type switch that determines the grip of an electro-magnet when the door is closed. Sends a signal if the magnetic grip is reduced from approximately one-third to one-half

Bored Lock (or Latch)

Lock or latch whose parts are intended for installation in holes bored in a door

Boring Jig

A tool holder and guide used to assist in lock installation. The boring jig can be set to the required backset and ensure proper location of the drilled holes

Borrowed Lite

A four sided steel frame, which is glazed (has glass) but does not include a door. Also known as a steel window frame


Small extension on the plug's body and the housing, which when lined up appropriately allows for assembly or disassembly of a wafer or wafer side bar lock. Also known as a Tab

Bottomed Out

The Tubular pick is inserted into the keyway until the head of the pick is flush with the lock's plug

Bottom Pins

They are cylindrically shaped pins, usually made of brass, which are used to set the depth combinations in pin tumbler cylinders. They are progressively varied in length and usually tapered at one end, enabling them to sit into the "V" cuts made in key blanks. When the proper key is inserted, the top of the bottom pin levels off at the plug's shear line allowing the plug to turn and activate the locking mechanism

Bottom Shoulder

On a single-bitted key, the stop near the bow, on the side opposite the cuts in the key blade

Bottom Tumbler

Varying length cylindrical shaped object which is positioned between the spring and top tumbler in the sleeve of a tubular lock


The handle or head of a key

Box Strike

A strike which uses a box to completely enclose the lock bolt. A box strike provides additional security and a cleaner appearing installation


The result which occurs when top tumbler(s) bind at the shear line in a tubular lock


See Break

Breakaway Padlock

A padlock whose shackle is made of brittle material. This type of padlock is commonly used on fire equipment and other items which must be easily accessible and yet secured. Also known as Frangible

Breech-Block Safe Door

A circular safe door that rotates to engage a set of lugs on the body of the safe

Bridge Rectifier

Converts AC voltage to DC


A special cutter tool used by lock manufacturers, which removes metal from a plug, in order to form the shape of the keyway

Broken Key Extractor

A locksmith tool used to remove a piece from a broken key, or other foreign matter, from the keyway of a lock

Builders Hardware

See Architectural Hardware

Builders Hardware Manufacturers Association

The trade association for North American manufacturers of commercial builders hardware. Also known as BHMA


1. In the impression system of key fitting, to move the key blank against the bottom pins or wafers in the cylinder, in order to cause impressions on the surface(s) of the blank. 2. See also Rap

Burglar Alarm

A device or combination of devices which detects and reacts to an attempted intrusion or to the presence of an intruder. Also known as an Intrusion Alarm

Burglar Proof Spindle

A tapered or shouldered spindle, with hardened pins or entirely hardened, designed to prevent punching, pulling and drilling

Burnishing Tool

Tool used to clean relay contacts


Chips or filings which remain on the blade of the key after it has been cut. Burrs usually occur when the cutter has worn. The burrs can be scraped or buffed off using a file or wire wheel


A lining used to reduce friction between a fixed and movable part. Bushings are made of soft metals and plastics

Butler's Door

Wooden doors which swing both in and out. These spring operated hinges are designed to keep the door open at a ninety degree angle on either side

Butt (Hinge)

A type of hinge designed for mortising into the edge of the door and into the rabbet of a door frame

Butterfly Cam

See Clover Leaf Cam

Butterfly Knob

A small piece of metal in the center of many manipulation resistant combination lock dials. In this type of lock, the butterfly knob must be turned when the combination has been dialed in order to lower the fence and retract the bolt

Button Contact

Enclosed switch mounted in door or window frame

Bypass Method

A method of gaining entry in which the part of the lock mechanism that is directly operated by the key (for example, the cylinder) is bypassed. The opening of a door by shimming its spring latch with a plastic card would fit into this category of entry method


C–Go to Top

Cabinet Lock

A relatively small type of lock designed to be used on pieces of furniture and very thin doors. Cabinet locks can be operated by a key, combination dial or push buttons


A bundle of wires covered by the same covering

Cable Lock

A type of lock whose locking member is a length of cable, which is passed through the object to be locked


A precise measuring instrument that can determine depths of cut, as well as inside and outside diameters


1. The part of a lock or cylinder which activates the bolt or latch as the key is turned. 2. A tailpiece which mounts flat onto the rear of the plug, whose operating portion is at a ninety degree angle to the plug. The cam may also act as the bolt

Cam (of a cylinder)

A rotating piece attached to the end of the cylinder plug to engage the locking mechanism

Cam Lock

A lock, often used on drawers and cabinets, which has a cam bolted to the back of its cylinder plug. The cam serves as the locking bolt. There are standard, high security, and tubular styles of cam locks

Cam Plug

A narrow stile door lock component which operates in conjunction with a lever handle to retract the dead latch

Cane Bolt

A heavy cane-shaped bolt with the top bent at right angles; used on the bottom of doors


1. The face plate component on the lock. Some lock types have built-in capts, while others have replaceable caps. 2. The spring retainer used on certain types of interchangeable cores

Capacitance Detector

A device which detects an intruder containing or in close proximity to a metal object. See also Safe Alarm

Capacitor (CAP)

An electronic component used throughout electronic circuitry for filtering, timing, current limiting, and many other uses. The value is usually expressed in terms of micro-farads and the voltage rating in terms of either AC or DC working volts

Capping Press

A manual press designed to remove and install pin chamber caps from certain styles of interchangeable cores

Card Operated Lock

A type of card access control system that is activated by inserting a card into a slot instead of using a key or dialing a combination. Using the correct card permits access through the locking door(s). There are three major types of card technologies: the Wiegand, mag-stripe, and the proximity

Card Reader

Part of an access control system through which the card is read. There are swipe, slotless, and proximity card readers

Cart Bar / Crash Bar

A bar or series of bars mounted on a door panel to protect it and the glass from breakage


The part of a key machine that holds the key vise or vises

Carry Bar

A bar mounted onto the inactive door to automatically open the active door whenver the inactive door is opened


The housing, usually metal, which contains the lock mechanism

Cased Opening

A steel frame with no stops

Casement Hinge

A hinge to swing a casement window. The term is often used to describe a hinge designed to throw the sash out far enough to permit cleaning the outside of the glass from the inside of the room on an outward-swinging casement

Casement Window

A window whose sash is hinged along one side and usually has a crank to operate window

Case Hardened

Metal lock parts which have been processed and strengthened to better resist attack. Case hardening is usually used on combination lock shackles, hasps, and bolts

Cash Drawer Cylinder

A modified mortise cylinder used in cash drawers. This type of lock cylinder usually part of its housing removed to ensure positioning within the drawer


A mis-cut key in which one or more of the tumblers binds against the housing or the plug as the key is turned. This can result when one or more of the cuts in the key is too deep or shallow


Acronym for Closed Circuit Television


Indicates that the individual so identified is a Certified Door Consultant and member of the Door and Hardware Institute

Central Station

A company that monitors residences and businesses that have certain alarm systems. These companies "monitor" these locations 24 hours a day, 365 days a year for a monthly fee

Centrally Monitored Alarm

An alarm system which when activated sends a signal over phone lines or wires to a police station, guard booth or central station

Ceramic insert

A piece of ceramic material that is built into a dead bolt, to protect the bolt against sawing. The ceramic insert is used mainly on narrow style bolt locks

Certification Label

A label placed on a device to indicate compliance to applicable standards. Such labels can include UL, C-UL, CSA, ETL, TUV, etc.

Chain Bolt

A spring bolt actuated by a chain attached to the spring bolt for application at the top of the door

Chain Door Fastener

A device that limits the opening of a door by means of a chain

Chain Door Lock

A type of lock that has as its locking member a length of chain, and is used on a door, to eneable the user to open the door a fixed distance without having to completely unlock the door

Chamber Capping Pin

A small, disc-shaped piece of metal that is used to seal off the top of a pin chamber. This is used in certain types of removable core cylinders

Chamber Capping Screw

A small, headless screw, usually of the type driven by a hex key, which is used to seal off the tops of individual pin chambers in a certain type of pin-tumbler cylinders


The degree of beveling on the ends of cylindrical lock pins and tubular lock tumblers

Change Key

1. A key for operating a specific lock or group of locks having the same planned bittings. 2. The lowest level key in a master key system. 3. A special key designed to unlock combination lock wheels in order to change the combination. See also Safe Change Key

Changeable Bit Key

A type of bit key where the bit is made up of small sections, which can be taken apart and rearranged to make different combinations

Changeable Lever

An adjustable lever consisting of a detent and sweep lever. The detent lever is unlocked from the sweep lever with a change key


In lock terminology, this word usually means the different key bitting, tumbler arrangements, or combinations in a series of locks

Changing Index

The indicating mark on the dial ring used when changing the combination of a key change combination lock. Changing index may be located anywhere on the dial right

Check Valve

A device in some door closers which allows fluid to flow in only one direction

Checking Floor Hinge

A device placed in the floor that combines top and bottom pivots for hanging the door with a controlled speed dosing mechanism

Chuck Key

A tool used to tighten and loosen a drill chuck from around a drill bit

Cipher Lock

A lock that is opened by pressing its buttons in a specific sequence. It differs from a coded lock in that it typically has only 4-5 buttons, and each button can only be pressed once. The cipher lock was the mechanical precursor of today's electronic coded lock with a telephone-like keypad


A path through which current can flow from the source through conductors and electrical devices and normally returns to the source. A closed circuit is a complete path for current to flow from the source and return to the source. Closing a switch allows current to flow as opening a faucet allows water to flow


Combination lock types are classified by Underwriters Laboratories using a Group designation including Group 1, Group 1R, and Group 2. These classifications are determined Underwriters Laboratories Standards for Safety. There are other classifications and other testing laboratories


Latchbolt is operated by rotating the inside lever, or rotating the outside lever only when not locked from the inside or outside key. Outside lever is locked and unlocked by turning the key inside or outside lever. Inside lever cannot be locked

Classroom Function

The inside knob or lever works at all times, but outside knob or lever works only when not locked by key. BHMA function 08

Clean Room Door Package

A door package that has special seals and characteristics to meet stringent air or particle infiltration specifications


A metal link for attaching a chain to a padlock


See Hand Held Code Key Cutter

Closed Circuit

A complete circuit in which current can flow

Closed Circuit Television

A self contained system for producing televised images. Commonly used for security surveillance. Also known as CCTV


See Door Closer

Closer Reinforcement

A reinforcing piece inside of a door or frame. Provides additional strength of attachment of door closers

Closing Pin

In some removable core cylinders, the top pin, or last pin inserted into a pin chamber before the spring is identified as the closing pin

Clover Bow Key

A design of key that has a bow or head with three lobes, in a pattern resembling a leaf or clover

Clover Leaf Cam

In certain types of mortise locks, a cylinder cam that has three lobes, instead of just one, to activate the boltwork of the lock

Clutch Mechanism

Components of most double cylinder locks which transfer rotational motion from one of the cylinders to operate th elocking mechanism. At the same time not requiring the second cylinder's plug to rotate


An arrangement of numbers and/or letters by which a finished key can be made to operate a lock without having the original key. The code can occasionally be found on the key or lock. Therefore four types of codes: direct digit codes, silhouette codes, derivative or conversion codes, and regular key codes

Code Book

A book used by locksmiths to translate code numbers into depths and spaces, in order to originate a key to operate the lock

Code Card

Specific sized cards with m anufacturers space and depth information. These cards are designed to operate with certain code machines in order to originate keys

Code Cutter

A non-motorized machine used to originate keys. Code cutters use punch and anvil technology to make the cuts in the key

Code Machine

A device for originating a key when the depths and spaces are known

Code Number

A series of number and/or letters stamped into the head of some original keys and/or stamped in various locations on locks. This code number is then referenced in a code book to determine the tumbler depths in the lock

Coded Lock

A lock that is opened by typing a code on a keypad

Coilspring (Compression)

A spring made of wire coiled into a helix. A common spring of this type is a cylinder spring

Coilspring (Tension)

A spring made of wire coiled into a helix with the coils in close contact and an eye at each end to enable the spring to be stretched as the bolt or other parts move


1. The side bar in a type of pin tumbler cylinder that uses twisting pins and a number of possible different angles of cuts on its keys. 2. A comb-shaped tool which is used to lift the springs in a wafer side bar lock. THis tool enables the lock to be manipulated without knowing the depths of cut


The set a combination in a lock cylinder or key


1. This term denotes the grouping together of cuts on a key, especially when different arrangements are possible. 2. The arrangement of numbers which a combination lock is set

Combination Anchor

A device for anchoring a frame to wall constructed with wood or metal stud

Combination Change

1. The act of rearranging tumblers in a lock so that the original key will no longer operate. 2. The act of rearranging the numbers which a combination lock is set

Combination Changing Index

See Changing Index

Combination Dial

In a combination lock, the circular knob that has an array of numerals and lines, or letters, around its rim

Combination Padlock

A padlock that can be opened by entering a certain combination of numbers and/or letters on a dial, or on a set of wheels or push buttons. These locks are available with resettable or fixed combinations

Combination Wafer

Used in the Schlage wafer locks, the combination wafer requires a cut in the key to enable it to stay in the unlocked position. In this position, no part of the combination wafer crosses the shear line

Combination Wheel

The part of a dial-type combination lock that discriminates between a correct number and an incorrect one, when the combination is dialed. See also Wheel


The terminal in an alarm system which completes a circuit with a normally open or normally closed contact

Common Power Source

A single source of power which is used to operate the lock(s), the reader(s) and the control unit. This avoids the need for separate transformers or power supplies. Highly advantageous especially if access control system has back-up power supply

Communicating Door

A door between two adjoining rooms which are both on the inside of a building, such as two hotel rooms or two offices

Communicating Door Lock

A lock specifically designed for communicating doors which have the ability to lock the door from either side usually requireing a key to unlock from opposite side

Complementary Keyway

A keyway in the plug of a wafer or disc tumbler lock that will accept more than one key section. See also Composite Keyway

Composite Keyway

A keyway in the plug of a pin tumbler lock that will accept more than one key section. See also Complementary Keyway


To defeat a lock, security, or access control system. To gain unauthorized entry

Compression Ring

The compression ring encircles the face and provides a space adjustment range to cover exposed portions of the mortise cylinder

Concealed Cylinder

A style of mortise cylinder which is designed to be positioned behind an armored front with only the plug face exposed


A conductor is asubstance that offers very little resistance to current flow. Examples are copper, silver, gold and platinum

Conical Spring

A piece of round spring wire that is wound into a cone shaped spiral, and which is used in certain heavy duty key-in-knob locks

Connecting Bar

See Cylinder Bar

Connecting Rod

Found in the door, deck and tailgate locks, connecting the pawl and the locking mechanism

Console Lock

Automobile lock designed to secure the console door

Construction Ball Bearing

In a lock cylinder that is part of a construction master key system, one of a group of ball bearings which allow the construction master key to operate the cylinder, until the construction master key is voided by turning the cylinder plug with one of the permanent keys. Three ball bearings are in pin chamber five of the lock cylinder illustrated

Construction Master Key

A temporary master key, used during the construction of a building. When the building becomes occupied, a device can be activated within each of the locks causing the construction master key to be voided from that point on. After this has been done, the permanent keys will operate the locks


Electrically conductive points, or sets of points, used to make or break an electrical circuit mechanically

Contact Cleaner

A liquid which, when sprayed onto an electrical contact, or into a lock, has a cleaning effect

Contact Points

The numbers which come up under the opening index of a combination lock when the nose of the lever contacts the sides of the gate in the drive cam. The right contact area is determined by rotating the dial to the left and the left contact area is determined by rotating the dial to the right

Contact Rating

Maximum load rating of a switch, stated in voltage and/or current

Contact Smart Card

A smart card that must make contact with the reader. Compare with contactless smart card

Contactless Smart Card

A smart card that uses RFID technology to enable its use without physical contact with the reader. Maximum distance from the reader is either the proximity range (10 cm. / 4 inches) or the vicinity range (one meter / 3 feet) depending upon which of two RFID standards is used

Continuity Measurement

A test performed on a wire or electrical circuit to verify that there are no open lines or poor connections

Continuous Duty

Refers to a device or a control that can operate continuously with no off or rest periods

Continuous Hinge

A hinge designed to be the same length as the moving part to which it is applied as, for example, the lid covering the keyboard of a piano

Continuous Output

The normal voltage available from a power supply


To limit access through electronic and/or mechanical equipment

Control Key

A special key used to remove the core from removable core cylinders and from interchangeable core cylinders

Controlled Cross Keying

Two or more change keys under one master key operating one cylinder

Control Pin

In specific styles removable core or interchangeable core cylinder, a pin that is raised by the control key to the level at which it is flush with the top of the control sleeve. The control pins allow the control key to perform its job of removing the core from its housing

Control Sleeve

The part of removable core or interchangeable core cylinder which surrounds the plug, and which will be operated by the control key

Control Unit

Contains the microprocessor and program memory for an access control system

Convenience Key

Key which can enter into keyway with either edge of blade facing up. Single sided convenience key operates a lock where all the tumblers come from one side and a key could be cut only on one side and still operate the lock. The key is then duplicated on the other side. Double sided convenience key refers to double throw tumblers, which enter the keyway from both directions and require the key to have cuts on both sides. Both sides of the key are cut identical

Conversion Code

See Derived Code


A device used on a pair of doors to ensure that the inactive leaf is per mined to dose before the active leaf. Necessary when an overlapping astragal is present and exit devices, automatic or self-latching bolts are used with closers on both door leaves. See also Door Coordinator

Copy Dog

See Guide


The unit which contains the tumbler springs and the mechanism which locks and unlocks the locking mechanism. Another term for Interchangeable Core

Corner Bracket

A bracket used to mount a door closer on the top side of a door. When the door is opened, the bracket and closer remain in the door opening

Corrugated Key

A key with pressed longitudinal corrugation in its blade to correspond to an irregular shaped keyway

Cotter Pin

A malleable metal pin, whose halves form a cylindrical shape. These halves separate to secure components together


Lid for a lock case

Cover Plate

1. Cast metal plates designed to cover and protect the locking mechanism on certain styles of locks. 2. A formed metallic plate used to strengthen and cover a damaged door. See also Horn Plate

Cover Screw

A machine thread screw used to attach the cover to a combination lock case

Crash Bar

See Panic Bar or Exit Device


A medium that contains encoded information, such as ID cards, key fobs, & smart chips

Cremone Bolt

A device of surface application that, by a turn of knob or lever handle, locks the door or the sash into the frame, top and bottom

Cup Escutcheon

A door plate, for use on sliding doors, having a recessed panel to afford finger hold and to contain a flush ring and sometimes a cylinder, all being flush with the surface of the plate

Cross Bore

A hole drilled from side to side of a door. This opening is used to mount the lock


See Interchange

Crossover Foil

Special foil made of tinned shim brass or mylar tape which is used to foil over wood or metal cross bars on windows

Crow's Foot Mark

On certain combination lock dial rings, an opening index which resembles the letter "Y", with the vertical line extended upward


A style of pin tumbler lock cylinder and key. The face of the keyway is an "X" or circle and there are tumblers on three or four sides of the key. Also known as Cross Keys and Locks


The flow of electricity through a conductor measured in amps

Current Transfer

Products that are designed to carry current to a locking mechanism mounted into a door. There are door cords and electric hinges

Curved Lip Strike

A strike plate whose lip is curved to conform to the detail of the door casing. There are a number of styles of curved lip strikes, including the standard lip, the ANSI preparation strike, the raised lip, and the full lip strike

Customer Key

See Renter's Key


The indentation in a key made to fit the tumblers in a lock. Any notch or milling made in a key is known as a cut, whether it is angled, square, or curved. Cuts in key blanks are also known as bitting

Cut Depth Number

A short number, usually having only one digit which is used as a shorthand way to represent a cut depth. For example a number 3 cut might stand for 290 thousandths of an inc (0.290)


The cylindrical cutting tool used on a key machine to originate or duplicate keys. There are cutters designed for orientation, duplication, and brass and steel key blanks

Cutter Vise

The vise(s) of a key machine that holds the key and/or key blank for th epurpose of originating or duplicating a key

Cutout (door)

A piercing for hardware, lite, louvers, and/or accessories

Cylinder (of a lock)

The cylindrical-shaped assembly containing the tumbler mechanism and the keyway, which can be actuated only by the correct keys

Cylinder Bar

The part of a lock cylinder (such as a rim cylinder or a key-in-knob cylinder) which transmits motion from the plug to the boltwork of the lock. Also known as Connecting Bar

Cylinder Bar Shutter

In a rim lock, a sliding piece of metal designed to cover the hole into which the cylinder bar fits, if the cylinder is pulled out of the door

Cylinder Barrel

See Cylinder Plug

Cylinder Body

See Cylinder Housing

Cylinder Cam

The part of a lock cylinder that transmits motion from the plug to the mechanism of the lock, usually a mortise lock

Cylinder Cap

A threaded part in certain types of locks, which is used to hold the plug within the cylinder body

Cylinder Cap Pin

A long, thin, cylindrical pin which has a narrow section at its tip, and is used to hold the cylinder cap stationary on the end of a pin-tumbler cylinder plug

Cylinder Collar

A plate or ring used under the head of a cylinder. See also Cylinder Ring

Cylinder Drill Jig

A positioning template for drilling through the shear line in cylindrical locks

Cylinder Driver

A circular piece of metal which secures the cylinder bar to the rear of the plug. The shape of the cutout in the cylinder driver varies depending upon application

Cylinder Driver Bar

A cylinder driver and bar built into one unit

Cylinder Guard

A device used to protect the cylinder of a lock, leaving it less vulnerable and more able to resist being drilled or wrenched from the door. In addition, there are cylinder guards that protect the face of the cylinder

Cylinder Housing

The external case of a lock cylinder, which contains the plug, tumblers, and springs. Also known as the shell

Cylinder Key

A key for a lock which has its tumblers contained within a cylindrical enclosure, such as a key for a pin tumbler lock, or a wafer tumbler lock, among other types

Cylinder Lock

A lock in which the locking mechanism is controlled by a cylinder

Cylinder Plug

The movable part of a lock cylinder that contains the key slot or keyway into which the key is to be inserted

Cylinder Puller

A tool for forcibly removing the cylinder from the locking mechanism. There are cylinder pullers for residential/commercial locks and automobile locks

Cylinder Retainer

A part that holds a cylinder in its lock. There are retainer pins and crescent shaped retainers. Some lock cylinders are retained by more than one cylinder retainer. A cylinder retainer can be part of the lock or part of the housing assembly which contains the lock

Cylinder Ring

A circular piece of metal, used to take up the space between the front lip or edge of a lock cylinder and the escutcheon or door in which the cylinder is installed. There are standard length cylinder rings and adjustable cylinder rings. Also known as Cylinder Collars

Cylinder Scalp

A secondary face mounted onto the front of mortise and rim cylinders. The scalp contains the lock manufacturers name. Custom labeled scalps are available

Cylinder Screw

The set screw that holds a cylinder in place by preventing the cylinder from being turned after installation

Cylinder Spindle

See Cam and Driver

Cylinder Spring Retainer

Various shaped metal components which are designed to keep the springs and tumblers within the lock cylinder. There are flat spring retainers which secure all of the tumblers and springs and there are singe retainers which secure the spring and tumblers in only one pin chamber

Cylindrical (locks and latches)

A term used to describe bored locks, which have a cylindrical case into which a separate latch bolt case fits

Cylindrical Lock

1. A lock designed to be installed into round holes drilled in the door. 2. A lockset having the cylinder(s) contained in the knob(s). Also known as a bored lock, a key-in-knob lock and cylindrical dead bolt locks

Cylindrical Lock Prep

Cutout (or hole) in a door for bored/cylindrical locksets. Also known as 161 Prep

D–Go to Top

Data0 (D0)

One of two data lines in Wiegand communications. Data0 (D0) represents the binary "0"

Data1 (D1)

One of two data lines in Wiegand communications. Data1 (D1) represents the binary "1"

Day-Night Control

A control instrument which can be wired with two protective circuits. The day circuit is on 24 hours a day; the night circuit is only on when the premises are closed


Abbreviation for Decibel


Abbreviation for "Door Cut Down Bottom" - Cut door undercut

Dead Bolt

A lock component which projects from, and is withdrawn into, the lock case by action of the lock mechanism. When the door is closed and the dead bolt thrown, it extends into the strike, locks the door, and does not release with end pressure

Dead Bolt Lock

A single or double cylinder lock whose bolt mechanism becomes locked against end pressure when projected. There are a variety of styles and grades of dead bolt locks

Dead Latch

Aluminum narrow stile door locking mechanism that operates using a spring loaded latch


A lock equipped with a dead bolt only

Dead Locking Latch

1. A type of latch which, once it has been extended into its strike plate on the door frame, resists any attempt to push it back by end pressure or by shimming. 2. A type of lock that has such a latch as one of its working parts. Also known as a Dead Latch

Dead Locking Padlock

A padlock that must have the shackle in the locked position befroe the key can be removed. This type of padlock can never be left unlocked without leaving the key in it

Deadlocking Plunger

The plunger on a deadlocking latch that stops against the face of the strike. Positioned in this location, the latch can not be retracted by foce

Dead Pin

A small diameter metal rod mounted onto the face of the inner bushing in a position which restricts the entry of a standard tubular key or pick

Dead Trap

A trap in which the trap wire carries no current

De-Burring Tool

A bladed tool designed to remove burrs from cylinder pins and pin chambers

Decibel (db)

An increment of measurement used to compare measured levels of sound energy (intensity) to the apparent level detected by the human ear. A sound that has 10 times the energy of another sound is said to be 10 decibels louder; 100 times the energy is 20 decibels louder; 1,000 times the energy is 30 decibels louder and so on. Decibel levels are correctly expressed as the number of decibels at a measured distance from the source of sound (for example, 125dB at 10 feet)


1. To determine the depths of cut in a key. 2. To determine the tumbler depths in a lock in order to originate a key

Deep Master Key

A type of master key that has none of its cuts made shallower than the corresponding cut of the individual keys. This type of master key should not be used, because any individual key in the system can be cut down in order to make such a master key

Delay Exit Control

Controls the amount of time for the door release delay while at the same time the door will be released immediately for an emergency or power failure

Delay On Break

A term used to describe a mode of operation relative to timing devices. The delay begins when the initiate switch is opened (delay on break of initiate switch)

Delayed Action

An optional feature for door closers that permit the door to swing more slowly from fully open to just prior to the sweep range. This enables slower moving individuals (i.e. handicapped and equipment movers) to get safely through the door

Delayed Egress

An irreversible time delay built in the locking device of an opening preventing immediate egress

Deposit Safe

A safe with a slot or hopper into which money can be inserted

Depth Key

1. One of a set of lever-tumbler keys which has a flat surface of constant depth all the way along its length. It is used together with a spacing key, in order to make a lever tumbler key by number. 2. See Guide Key

Depth Gauge

A device to determine the depths of cut in a key. Depth gauges are commonly produced by lock manufacturers for their own key depths

Depth of a Cut

The amount of metal remaining on a key in a given cut position. This is measured from the root of the cut to the bottom of the key blade

Depth of Security

Concentric perimeters of security having different or increasingly stringent access methods. An inner area is protected both by its own access methods and by those of the areas that enclose it and must therefore be entered first

Derived Code

A series of code numbers which is derived from another series of such code numbers, by performing some mathematical operation, such as adding or subtracting a constant number. Also known as a Conversion Code

Detection Area

The area in which a detector can accurately measure disturbances. This area is determined by walls, doors, and other obstructions

Detection Pattern

The shape of the detectors sensing capability. The pattern is different for passive and active sensors, as well as differences within each

Detector / Sensor (Motion)

A device designed to detect the movement of a person or object in the vicinity of the doorway and signal the door control. Four types are in use today. They are: Infrared (Active) - A device that emits infrared energy and detects the amount reflected from people. The pattern can vary in size from narrow to wide, depending on design. Infrared (Passive) - A device designed to detect a change in temperature gradient. These devices do not emit any energy, but only detect infrared energy differentials. Microwave Unit - A device that operates on the Doppler radar principle, designed to detect moving people. Microwave units use antennae designed for varying pickup patterns usually described as either wide or narrow. Microwave units are normally either the directional or non-directional type. Visual Image Processing - A device that uses camera (s) along with digital signal processing to detect motion of people within the defined zone of the camera’s field of view

Detector / Sensor (Presence)

A device designed to detect the presence of people in the vicinity of the doorway and send an activating signal to the door control. Four common types are in use today. They are: Holding Beam - An infrared device used to activate, re-activate, or hold open a sliding door. It is used as a safety device to hold the door open. There are two types on the market. One uses a separate transmitter and receiver, the other uses a transmitter/receiver in one unit with a reflector. Both types use pulsed infrared as the detecting medium. Infrared (Active) - A device that emits infrared and detects the amount reflected from people. The pattern can vary in size from narrow to wide, depending on design. For sensors that are capable of learning different environments, the standard establishes a 30 second minimum learning time. Ultrasonic - A device that uses a transducer or transducers to emit high frequency sound to detect the presence of a person through echolocation. The pattern from a transducer is narrow and precise in range and transducers can be combined to produce a larger detection area. Visual Image Processing - A device that uses camera(s) along with digital signal processing to detect presence of people within the defined zone of the cameras field of view

Detent Lever

A lever that can be disengaged and displaced by the rotation of a change key. Detent lever disengagement permits the lift radius of its companion sweep lever to adjust to a cut in a set-up or renter's key


Anything that discourages an unauthorized entry. An alarm system or a dead bolt are considered good deterrents


A numerically calibrated part used to control the position of the wheels of the combination lock and operate the bolt when alignment is attained

Dial & Ring (Spy-Proof)

Transparent dial and ring permits inspection of vital areas and restricts unauthorized observation


1. A device for transmitting alarm signals over telephone lines using a communicator that sends a message to a receiver. The receiver is usually a central station. 2. A tool that will automatically dial all combinations in order to unlock a safe. The dialer tool is designed to be mounted onto the combination lock dial. Once programmed, it will dial any or all combinations

Dial Read Out Micrometer Key Machine

A type of micrometer key machine which displays the measurements of depth and spacing as divisions on a set of dials. See also Micrometer Key Machine

Dial Ring

The part directly around the dial and on which is located the opening, changing and L.O.B.C. indices. L.O.B.C. is an abbreviation for "Locked On By Combination"

Dial Ring Bearing

A specialized plastic component which mounts into the center of specific models of dial rings and acts as a bearing surface for the dial and spindle. This bearing is made of plastic in order not to conduct electricity, making it impossible to decode the lock using electricity

Dial Shield

A housing used to shield the combination lock dial from unauthorized observation

Dial Spindle

In a combination lock, a threaded metal rod that is usually attached at one end to the combination dial, and the other end screws into the drive cam


A tool used for the cutting of threads on an external surface

Die Cast

Formed by casting of molten metal in a permanent die

Digital Keypad

An electronic input device with a varying number of keys

Digital Lock

A lock which uses a series of numbered and/or letter push buttons for opening. A digital lock can be mechanically or electronically operated

Dimple Key Machine

A key machine designed to duplicate high security keys which have drilled indent cuts in the sides and/or edges. Also known as a Multi-Point Machine and a Drill Style Key Machine


An electronic component that will only pass current in one direction. Commonly used in door controls for rectifying AC to DC

Dip Switch

A small type of gang switch used on circuit boards for mode selection. Acronym for a switch that mounts in the same socket of circuit pattern as a Dual-In-Line I.C. that are normally called dual-in-line packages; hence D.I.P.

Direct Current

A current that flows in one direction only and constant magnitude for a given load. Direct Current flows when the polarity remains constant with time. Direct current is supplied extensively in electronics and low power applications. Direct current can be obtained from DC power supplies or by adding a silicon rectifier to an AC current. Direct current is measured in amperes; "I" or "A"

Direct Digit Code

A type of code in which the digits are the cut numbers of the key. This type of code number may be read from bow to tip, or from tip to bow, depending on the make of the lock. Direct digit codes can be stamped into keys, tail pieces and lock housings


To turn off an alarm system

Disc Tumbler

The disc tumbler is a double acting, spring loaded flat plate designed to slide in slots which run through the diameter of the cylinder plug. See wafer plug

Display Key

A key used in a hotel lock system, which will open and lock one particular guest room from the outside. This key prevents all other keys from operating the lock. The only key that can unlock this room is an Emergency Key


1. To lock the exit devices in the unlocked position, so that the door can be opened from either direction. 2. See Dogging Key and Locking Dog

Dogging Device

As used in exit devices, a mechanism that fastens the cross bar in the fully depressed position, and also retains the latch bolt or bolts in a retracted position, thus permitting free operation of the door from either side. See also Dogging Key

Dogging Key

A special key that is used to hold down the bar of a panic exit lock. The purpose of the dogging key is to keep the panic exit device in the unlocked position. This is normally done during business hours and save wear and tear on the panic device. This key is often in the form of a hexagonal rod with a triangular or round head. Also known as a Dogging Device


A movable panel or leaf used to close an entryway

Door Bolt

A manually operated rod or bar attached to a door providing means of locking

Door Chain

See Door Guards

Door Check

See Door Closer

Door Closer

A device used to control the action of a door by use of either hydraulic pressure, high tension spring, electrical devices, or air pressure. Single acting door closers operate doors which swing in one direction from frame to open and back to frame. Double acting door closers operate doors which swing in both directions, the closing point is the frame. A positive centering door closer is a double acting door closer which is specifically designed to stop at the dead center of the door frame every time. Also known as a Door Check

Door Closer Arm

On conventional door closers, the arm is the connection between the door and the closer or the jamb and the closer

Door Closer Bracket

A device whereby a door closer may be installed on the frame rather than directly on the door

Door Closer or Check

A device combining a spring for dosing and a compression chamber into which the liquid or air escapes slowly, thus providing a means of controlling the speed of the dosing action

Door Contact

A means of detecting whether a door is open or closed. Notifies when the door is held open or entry is forced

Door Coordinator

A piece of hardware that is used on a pair of doors, in order to hold the active door open until after the inactive door closes

Door Cord

A surface mounted, flexible cord containing wires used to carry current to and from contacts mounted on doors and some movable windows. Door cords can be used in place of electric hinges and pivots. Also known as Door Loops and Flexible Conduits

Door Edge Pin

A pin installed into the hinge edge of an outswing door. This pin secures the door even if the pins are removed from the hinges. Also known as an Anti-Liftout Pin

Door Edge Shield

A piece of metal with a U-shaped cross section, that is wrapped around the edge of a door to protect the area of the door in which the lock and latch are installed. Also known as a Door Plate

Door Filler Plate

Metal plates designed to convert a door edge opening to a different application. Door filler plates are used to convert larger openings to accommodate smaller lock applications

Door Guards

Secondary door locking mechanism which permits the door to open slightly. There are two styles of door guards; chain and hinged bar. Also known as a Door Chain

Door Hardware

Components whose primary application is to be mounted on a door. These components mare or may not contact the door frame

Door Holder

A device that holds a door open at selected positions

Door Lock

1. Locks designed to secure a door. There are a variety of door locks including key-in-knob, dead bolt, and mortise locks. 2. Locks designed to secure a cabinet door

Door Loop

See Door Cord

Door Mounted Sensors

Sensors mounted on the door leaf such that they move with the door

Door Pivot

A hinging device embodying a fixed pin and a single joint. Most types include lateral fastening

Door Plate

Metallic plates which wrap around the edge of the door that contains the lock and or locking mechanisms. There are a variety of styles and sizes of door plates. See also Door Edge Shield

Door Position Indicator

A switch mounted into the frame of the door which signals the position of the door; ajar or closed

Door Pull

A handle mounted onto the door used to open the door. Door pulls are available in a variety of shapes and sizes

Door Release

An electronic mechanism which automatically releases the open door permitting it to close when smoke is detected. See Electromagnetic Door Holder

Door Stop

A device to stop the swing or movement of a door at a certain point. Also an architectural term defining that part of a door frame against which the door closes

Door Sweep

A weather brush or stripping used on the bottom of a door panel

Door Switch

A switch mechanism which activates and deactivates when the door is opened and closed

Door Thickness

1. The dimension of a door measured from side to side along one edge. 2. The measurement of a safe door from the lock mounting surface on the inside to the exterior face of the door

Doorway Viewer

A device that is mounted in a door, and enables a person on the inside of the door to view the area outside the door

Double Acting

1. Door or door closer which is designed to operate in both directions. 2. A wafer or disc tumbler is double acting. Moving in one direction from spring pressure, moving in the opposite direction when the key is inserted into the lock

Double Acting Operator

An operator that is powered when moving in one direction and is capable of moving manually in the other direction in emergency situations

Double Bitted Key

A key having cuts on both sides of the blade to active the tumblers of a lock

Double Bitted Lock

A wafer lock in which the tumblers are spring loaded from opposite directions

Double Circuit

A lacing, screening or foiling arrangement in which two adjacent patterns are installed; one pattern in the positive leg, the other into the negative leg or the protective circuit

Double Custody Lock

One that can only be unlocked when two different keys (usually possessed by two different persons) are inserted in sequence. Either key cannot open the lock alone

Double Cylinder Lock

A type of lock which has two cylindres (one on the inside of the door, and the other on the outside) to activate its locking mechanism. There are double cylinder key-in-knob locks, mortise locks, and dead bolt locks

Double Doors

A pair of doors that meet in the middle of the door frame when closed

Double Horn Safe Deposit Box

See Double Nose Safe Deposit Box Lock

Double Nose Safe Deposit Box Lock

A type of safe deposit box lock that has two extended copmonenets into which the key is inserted. The guard key enters one nose, and the renter's key enters the other nose. Also known as Double Horn Safe Deposit Box Lock

Double Pole/Double Throw

A term used to describe a switch or relay output contact form (2 form C) in which two separate switches are operating simultaneously, each with a normally open and normally closed contact and a common connection. This form is used to make and break two separate circuits. Abbreviation is DPDT

Double Sided Key Machine

A key machine designed to cut both sides of a double sided key at the same time

Double Throw

This refers to the ability of a switch or relay to direct current through more than one path. Double throw switches may be used on single or multiple pole switches

Double Throw Lock

One with a bolt which after the first throw can be extended further by an extra turn of the key or thumb turn. This type of lock mechanism requires two turns to withdraw the bolt when so locked

Double-Throw Bolt

A bolt that can be projected beyond its first position into a second, or fully extended one, thus providing extra security

Dove Tail Pin Tumbler

See Interlocking Pin Tumbler

Down-Hill Combination

A combination of cuts on a key in which the cuts become deeper and deeper from the bow to the tip. The use of such a key should be avoided, because it may become possible to pull the key out of the plug in positions other than the proper one or ones


Abbreviation for Double Pole Double Throw

Drawer Roller

A device used to ease the sliding of a drawer open or shut, usually with a metal or fiber wheel rotating in a metal frame

Drawer Slides

A mechanism employing guides and rollers that guide and support the drawer, permitting easy operation

Drill Gauge

A measuring plate with a number of different sized holes which are used to indicate the diameter of a drill bit

Drill Pin

A round pin extending from the interior side of a lock case opposite the key hole to accept a barrel key

Drill Resistance

The ability of a lock to resist unlocking when attacked with a drill

Drilled Key

See Barrel Key

Drive Cam

A circular safe combination lock component which transfers motion to the wheels and is gated to retract the bolt

Drive-In Latch

A latch with a cylindrical knurled ring around the face that will grip in the edge bore of a door when installed. Most common use of a drive-in latch is a metal door

Drive Pin

In a combination lock, the shaft extending from the underside of the drive cam and from all wheels but the most distant wheel. The drive pin is used to transfer motion from the drive cam is through the wheel pack


1. The upper pin in a pin tumbler lock. This pin obstructs the shear line when no key is inserted into the keyway. A driver is usually chamfered or flat on both ends. There are some locking systems which use varying length drivers to compensate for the different length bottom pins. 2. Metal part used to mount the cylinder bar onto the rear of a Schlage pin tumbler cylinder. The driver and cylinder bar are secured onto the rear of the plug using a cylinder cap. Drivers vary depending upon lock type and application. Also known as Top Pin

Driver and Cylinder Bar

These two components are mounted onto the rear of certain styles of pin tumbler cylinders. The driver and cylinder bar are secured onto the rear of the plug using a cylinder cap

Driver Pin Spacer

A thin spacer formed to serve as a drive pin


The upper set of pins in a pin tumbler cylinder, which, activated by the springs, project into the plug until raised by insertion of the key

Drop Escutcheon

One having a pivoted plate that covers the key hole


The number on a safe dial that lines up with the opening index when the fence falls into the slot in the drive cam

Drop Plate Bracket

A bracket used when the top rai of a door is too narrow to mount a door closer

Drop Relay

The relay used to latch the bell circuit (keep the bell or warning signal ringing)

Drop Ring

A ring handle attached to a spindle that operates a lock or latch. The ring is pivoted but remains in a dropped position when not in use

Dry Cell

A non-rechargeable type of battery

Dry Contact

Metallic points making (shorting) or breaking (opening) a circuit

Drywall Frame

A three piece door frame, installed after a wall has been erected


Two swinging doors, side by side, in a common header, that operate independently of each other and are separated by a vertical member

Dummy Cylinder

A mock cylinder without any operating mechanism for use where effect is desired

Dummy Knob

A knob, free or stationary, that only as trim hardware for the inactive door in a double door entry

Dummy Lever

A lever, free or stationary, that only as trim hardware for the inactive door in a double door entry

Dummy Trim

Trim only, without lock; usually used on the inactive door in a pair of doors

Duplicate Key

A key which is cut from the pattern of another


A rear cover for the inside of a strike plate. This finish component keeps wood and other building materials from passing back through the strike opening. Also known as a Strike Box

Dust Cover

1. A clear plastic shield used to keep fingerprints off the dial and dial ring of a combination lock. A dust cover is required on all G.S.A approved security containers. 2. An external cap used on some cam locks whose application is in adverse climate conditions

Dust-Proof Strike

A strike with a spring plunger that completely fills the bolt hole when the bolt is not projected

Dust-Resistant Cylinder

A cylinder, usually automotive or marine application which has a mechanism of spring-loaded shutters in or in front of the key slot. This is designed to prevent dust and dirt from damaging the internal parts of the cylinder

Dutch Door

A door having two separate leaves, hung one above the other. Also known as a Hollywood Door

Dutch Door Bolt

Device for locking together the upper and the lower leaves of a Dutch door


E–Go to Top

Edge Bore

A hole drilled into the edge of a door in order to install the latch and/or bolt mechanism of a cylindrical lock

Edge Plate

An angle or channel-shaped guard used to protect the edge of a door

Edge Pull

A pull mortised into the edge of a sliding door

Effective Plug Diameter

Dimension determined by adding the theoretical root depth of the key cut plus the factor length of the bottom pin. This length may or may not be the same as the actual plug diameter


Free access outside from inside

Ejector Punch

A narrow punch designed to remove the individual chamber capping pins from certain models of interchangeable cores

Elbow Catch

A spring-loaded device embodying a rocker arm and angle strike, for locking the inactive leaf of a pair of cabinet locks

Electrical Card Lock

A type of card-operated lock that depends upon electricity to function

Electric Eye

The light sensitive device used in photoelectric systems

Electric Latch Release

See Electric Strike

Electric Lock

A bolt or bar type locking mechanism that is only activated by electric current. An electric lock does not have a knob, thumb turn, or keyed cylinder

Electric Pick Gun

Battery operated picking instrument designed to vibrate all of the tumblers in a lock at the same time. This permits the tension tool to rotate the plug

Electric Strike

An electric door locking device (usually solenoid-operated) that will unlock the door when electrical power is applied to it. A fail-safe configuration will operate in the reverse condition (i.e., normally locked when power is applied and unlocked when power is interrupted). Previously known as an electric door opener

Electrified Lock

A type of lock that has been modified to be activated by an electric current. An electrified lock can also be operated as a mechanical lock


A coil of wire, usually wound on an iron core, that produces a strong magnetic field when current is sent through the coil

Electromagnetic Door Holder

Holds doors open using electromagnetic energy as part of a fire/security system. Door are released during an emergency

Electromagnetic Latch Release

A device used in conjunction with a vertical rod exit device on an automatic swinging door to coordinate the automatic door operator with the exit devices. Typically used on fire door applications


The reversible transformation of data from its original form to a format which is difficult to interpret. This is a mechanism to protect the confidentiality and integrity of the data and insure integrity. Encryption requires use of an algorithm and one or more encryption keys

End of Line Resistor (EOL)

Resistance in a supervised circuit, usually at the farthest point from the alarm control unit, restricting the flow of current to a known value which is monitored. Shorting the circuit in an attempt to bypass protective devices in the loop (i.e., door contacts) will create increased flow of current and cause an alarm. Opening (breaking) the circuit also triggers an alarm if the system is armed, or a supervisory signal, if the system is disarmed

Entry/Entrance/Office Function

Push button locking. Button on inside locks outside lever until unlocked by key or by rotating the inside lever. Inside lever always free

Electronic Lock

A lock primarily designed to operate electronically from the hand-set,/p>

Emergency Cam

In certain mortise type hotel or motel function lock, a cylinder cam that is able to be rotated only by the emergency master key

Emergency Exit Alarm Lock

See Exit Alarm Lock

Emergency Key

1. A shaped stamped metal key used on privacy type locks for emergency entrance. 2. A key used in specific applications, i.e. hotels, which can be used to open doors locked from the inside and/or can be used to lock out all other keys

Entrance Handle

An entry lock that uses a handle on the exterior side to push and pull the door. The lock cylinder is usually mortised into the door

End of Line Resistor

A resistor installed at the termination point of a monitoring circuit. Used to determine if wire has been cut

Engineer's Key

Single key that acts the same as a grand or great grand master key. This key permits entrance into rooms that contain the electrical, heating, maintenance, etc. This special key must be set up at the inception of the system

Entrapment Ball Bearing

In an entrapment cylinder, a piece of metal int he form of a sphere, having a very rough surface finish, and used for the purpose of trapping an unauthorized key by exerting a frictional force, which makes the key extremely difficult to remove

Entrapment Cylinder

A pin-tumbler cylinder that contains a device designed to trap and hold any unauthorized key that is inserted into the key slot

Entrapment Override Shim

A thin, flat piece of metal which, when inserted into the key slot of an entrapment cylinder alongside a trapped key, can be used to remove the key from the slot

Entry Control

Equipment specifically designed to control access through specific doors or gates. The equipment includes metal detectors, security intercoms, telephone entry systems, and video entry system

Equipment Locks

Specialized locks for securing equipment including tool boxes and power tools

Error Rate

Amount of mistakes when an access control system provides access to an unauthorized person or denies access to an authorized person,/p>

Escutcheon (Elongated)

A plate long enough to span a lock case and having holes for knob bushing, bit key, cylinder, turn knob and similar operating members as required,/p>

Escutcheon (Key)

See Key Plate

Existing Wall Anchor

An expansion bolt sleeve anchor, used to anchor a frame in an existing block wall. A reinforcement bracket and a punch-out & dimple prep through the stop of the frame is required for the sleeve anchor to go through

Exit Alarm Lock

A type of lock which can be opened from the inside of the door without a key in an emergency situation, and which sounds an alarm when this is done

Exit Device

A door-locking device designed to grant instant exit by pressing on a cross bar that releases the locking bolt or latch

Exit Latch

A paddle handle exit device. Pressing down on the paddle handle releases the locking mechanism

Expanding Plug Follower

A type of plug follower that expands in diameter to follow large plugs, and can be compressed to follow smaller plugs

Extended Bypass

The alarm sounds if the door switch (or bar switch) is opened in the armed condition. The key is required to reset the alarm. If the door switch is open, turning the key on, the unit will flash the red light twice. Once the door switch is closed, the unit will go through the arming delay mode and arm

Extended Lip Strike

A strike plate with a longer than usual lip. An extended lip strike is designed to be used on center hung doors and doors which will benefit from the longer strike lip

Extension Flush Bolt

A flush bolt in which the connection between bolt head and operating mechanism is by means of a rod inserted through a hole bored in the thickness of the door

Extension Link

A device used to provide long backsets in bored locks

External Relocking Device

A relocking device that is built outside the case of a combination lock (or key-operated lock). Often, such a device is built into the door of a safe

External Set Screw

In a mortise lock, a set screw that is accessed from the edge of the door, and which is used to hold the cylinder in the lock

Extractor Key

Used with construction master keying to remove the inserts from the keyway of each cylinder. There are pin tumbler and wafer tumbler cylinder extractor keys

Extra Duty Arm

A door closer arm option which is made of steel to handle the extra abuse


F–Go to Top

Face (of a lock)

The exposed surface that shows in the edge of a door after installation (See Front)

Face Plate

1. The part of a lock through which the latch and/or bolt protrudes and by which the lock is fastened to the door. 2. The plate through which the latch and/or bolt extends from the door

Facial Geometry

One of the physical traits that can be measured by biometric technology - the relative position of eyes, nose, and mouth on the face

Fail Latched

A locking device which activates at the loss of power. Latch mechanism controls door but does not necessarily restrict movement from secured side

Fail Safe

A term used to describe an electric lock that has a mechanical state of being unlocked and requires power to lock it. Also known as electrically locked. Detex abbreviation: FSA

Fail Secure

A term used to describe an electric lock that has a mechanical state of being locked and requires power to unlock it. Also known as electrically unlocked. Detex abbreviation: FSE

False Acceptance

In biometric identification, the erroneous result of identifying someone who isn’t in the database of known people. It is one of two ways biometric identification can fail; the other is false rejection

False Back Plate

A type of back plate that extends just slightly beyond the edge of the hole in which a rim cylinder is installed and is much smaller in area than the back of the case of the rim lock with which it is used

False Gate

1. In a lock tumbler a partially cut-out section, that is intended to make it more difficult to pick or to impression the lock. 2. A half deep gate in a combination lock which is intended to make it more difficult to manipulate the lock

False Rejection

In biometric identification, the erroneous result of failure to recognize a known person. It is one of two ways biometric identification can fail; the other is false acceptance


False Acceptance Rate. For a biometric device, the percentage of readings that are a false acceptance

Fast Pin Hinge

One in which the pin is fastened permanently in place


Abbreviation for "Frame Cut Down Bottom" - Cut jamb legs down in height

Feather Spring

A spring made of a flat strip bent approximately to a "V" to fit over a stamp in the lock case


The component on the lock bolting mechanism that enters the lever gates when they are properly aligned. Obsolete terminology is "the Stump"

Fiber Optic Transmission Systems

Multimode or single mode fibers designed to transmit signals using modulated light

Field Reversible

Handed locking products are considered field reversible if the arrangement of their parts can be changed to permit operation on a door which opens differently


A hardened steel tool with cutting ridges to form, smooth, or reduce the surface. There are several styles of files including round, pippin, and flat

File Cabinet Lock

A plunger style lock which is designed to secure the drawers of a file cabinet. There are round and square bolt types of file cabinet locks

File Card

A cleaning brush for files and key machine cutters

File Cutter

A style of duplicating key machine cutting wheel which produces a fine cut in soft metal key blanks

File Drawer Bar Lock

An after market locking bar mechanism designed to secure file cabinet drawers

Filler Plate

A blank plate used to fill mortised cutouts


Steel rod extending from the tubular pick which contacts and pushes against the bottom pins


The base metal, final coating and/or color on a lock, safe or door hardware. Lock and door hardware manufacturers comply with specific color standards

Finish Builders Hardware

Hardware that has a finished appearance as well as a functional purpose and that may be considered a part of the decorative treatment of a room or building. Also termed Architectural Hardware, Finish Hardware and Builders Finish Hardware


Federal information processing standard


Federal information processing standard for personal identification verification (PIV)

Fire Exit Bolt

See Exit Device

Fire Exit Hardware

Panic hardware which additionally provides fire protection when used as part of a fire door assembly and is labeled by a NRTL and is subject to follow-up inspection service

Fire Lite

A type of ceramic glass used in fire rated doors and frames

Fire Rated Door or Frame

The ability of a door or frames to provide an effective barrier against the passage of flames, smoke and toxic gases and/or to reduce the transmittance of radiated heat

First Key

A key originated from a key blank to fit a lock, without using a functioning key as a guide

Fixed Cam

A cam that fits tightly against the lock's plug. The cam, nor the plug, can rotate without first retracting the tumblers across the shear line. Also known as Rigid Cam

Flag Type Vertical Bolt Lock

A rim vertical bolt lock that has a readily-visible indicator to show whether the bolt is locked or unlocked

Flat Key

A key, usually stamped from flat material without grooves or millings. Also known as Flat Steel Key

Flat Slotter

Flat cutter designed to make depth cuts only. Flat slotters are available in a variety of thicknesses

Flat Steel Key

See Flat Key

Flip Lock

A door locking mechanism made up of two interconnecting metal plates. One plate is mounted into the door frame

Floor Anchor

See also base anchor

Floor Closer

A closing device installed in the floor under a door

Floor Hinge

A combined pivot hinge and closing device set either in the floor or in the bottom of the door. It may be spring type only or may be combined with liquid control

Flush Bolt

A door bolt so designed that when applied it is flush with the face or edge of the door. Door bolts are placed on the inactive door of a double door application

Flush Cup Pull

A pull mortised flush into a door, having a ring pull that folds Hat into the cup of the pull

Flush Door

A door without glass and/or louvers

Flush Ring

A flush door pull mortised in a door, having a ring pull that folds flat into the cup of the pull

Fluted-Head Screw

A type of screw that has a set of flutes or grooves around the rim of its head, parallel to the length of the screw


The part which makes contact with the drive pin for rotation of the wheels in a combination lock


Thin ribbon-like conductor placed on glass and hollow doors and connected into the protective circuit of an alarm system

Foil Protector

A special varnish used to coat foil to protect it from damage

Folding Door Lock

A lock which secures folding doors from sliding open

Follow Tool

A special tool used when removing a plug from the cylinder housing to simultaneously retain the spring loaded driver pins. It is usually a cylindrical straight smooth rod having a diameter similar to the plug. Follow tools are made of metal, wood and plastic

Foot Bolt

A type of bolt applied at the bottom of a door and arranged for foot operation. Generally the bolt head is held up by a spring when the door is unbolted

Force Gauge

A test device used to measure door opening and closing force

Fork Bolt

Latching mechanism used on some model compartment locks

Form C Relay

A switch mechanism which contains three terminal points: Open, Closed, Common


The way that the information (parity bits, facility code and card #) is organized on the credential

Frame Filler Plate

Metal plate designed to convert a frame opening to a different application

Frame Hardware

Components whose primary mount is onto the door frame. These components may connect with the door and/or affect the doors operation

Frangible Shackle Padlock

See Breakaway Padlock

Free-Spinning Cylinder Ring

A cylinder ring that, if turned by a wrench, would rotate without moving the cylinder

French Door

A wooden framed door containing a full length glass panel. This type of door usually requires a shorter backset lock and offers almost no security

Friction Catch

Any catch which when it engages a strike is held in the engaged position by friction. See also Ball Catch

Friction Hinge

A hinge designed to hang a door and hold it at any desired degree of opening by means of friction control incorporated in the knuckle of the hinge

Front (of a lock)

The plate through which the latching or locking bolts project (See Face)


False Rejection Rate. For a biometric device, the percentage of readings that are a false rejection


A term used to describe an electric lock that has a mechanical state of being unlocked and requires power to lock it. Also known as electrically locked. See also Fail Safe


A term used to describe an electric lock that has a mechanical state of being locked and requires power to unlock it. Also known as electrically unlocked. See also Fail Secure

Full Access Key

In a certain type of entrapment lock system, a key which will operate the lock at all times, whether the limited access key is programmed to work or not

Full Glass Door (Design FG)

A design of dor having louvers the entire height and width of the area surrounded by rails and stiles

Full Louver Door (Design FL)

A design of door having louvers the entire height and width of the area surrounded by rails and stiles

Full-Size Back Plate

A type of back plate that extends far beyond the edge of the hole in which a rim cylinder is installed, and is very nearly equal in surface area to the back of the rim lock case with which it is used. This type of back plate provides improved security against forced entry accomplished by pulling of the cylinder. See False Back Plate

Full Ward Ring

A ward ring that prevents rotation of its cylinder plug in either direction (clockwise or counter-clockwise), unless a notch is cut in the bottom of the key to clear this ward ring

Full Wave Bridge Rectifier

Electrical component which converts AC to DC. A full wave bridge rectifier is used on fail safe electric strikes, which lock when solenoid is energized. Also known as a bridge rectifier or a rectifier


1. The application of a lock, i.e. storeroom, entry, etc. 2. The electrical operation of locking and unlocking doors by means of a remote control

Fusible Link

A piece of soft metal designed to melt at low temperatures during a fire or from a surge of electricity. Fusible links are used on electrical components to prevent circuit overloading

Fusible Link Hold Open

A type of friction hold open in a door closer which will force an open door to close when the fusible link is melted during a fire

Fusible Link Louver

A louver used in fire-rated doors


G–Go to Top


A rubberized spacer used to weatherproof an outside electrical box and cover


The cutout in the circumference of a combination lock wheel which is engaged by the fence on the lever assembly

Gate Box

A metal box designed to contain entry and/or dead bolt locks to secure a metal gate or door. Most gate boxes are welded in place to provide the maximum security

Gate Cover

A plate which prevents the lever from entering the gates of zero change combination locks while the combination is being changed. A second function of the gate cover is to prevent insertion of the change key until the wheels are properly aligned

Gate Dead Bolt Lock

A single or double cylinder lock which uses a dead locking latch bolt. The gate dead bolt lock is used on some styles of swinging gate locks

Gate Lock

A lock and locking mechanism designed for swinging or sliding gates


A device for providing isolation and control of the flow of information between a computer and authenticated devices on the network


Wire size: higher gauge means thinner wire

Gear-Drive Combination Lock

A type of combination lock in which the motion is transmitted from the dial to the drive cam by a system of meshing gears

Gel Cell

A battery which uses gelled electrolyte rather than liquid electrolyte

Generation Key Cutting

Duplicating a key from a duplicate key. Generation cut keys are easily distinguishable because the cuts are rounded off, no longer sharp like an original key. The rounding off is the result of use and repeated duplications

Give-Away Ring

Inexpensive wire key rings given away by locksmiths when two or more keys are purchased

Glass Stop

Extrusions used to hold the glass in a door leaf

Glazing Bead

Removable trim at a glazed opening to hold glass securely in place

Goof Rings

Adapter rings for a cylindrical lock used when the cross bore opening is either too large or the hole has been drilled incorrectly. The most common application of a goof ring is to reduce the cross bore opening from 2-1/8" to 1-1/2" diameter. A Scar Plate can be used in place of a Goof Ring

Grand Master Key

A key that operates locks in several groups, each of which has its own master key

Grand Master Key Section Blank

A type of key blank that is designed to enter two or more groups of different key slots of keyways, where each group has its own master key section blank, and where each key slot has its own individual key section blank


A very soft form of the element carbon, which has been used by some locksmiths to lubricate lock parts. The use of graphite has been basically replaced by silicon based and other products for lubricating lock parts and mechanisms

Graphite Pin

In a certain type of construction master key system a pin tumbler which is made of a soft form of carbon

Graphite Pin Construction Master Key System

A type of construction master key system in which a pin tumbler made of graphite is used, so that this pin can easily be broken, to void the construction master

Gravity-Drop Combination Lock

A type of combination lock that depends on the force of gravity to enable the fence to enter the gates of its combination wheels

Great Grand Master Key

A key designed to operate all of the locks that are within the domains of two or more grand master keys

Great Grand Master Key Section Blank

A type of key blank which is designed to enter all of the key slots that are within the domains of two or more grand master key section blanks

Great Grand Master Key System

A great grand master key with two or more grand master key systems set up under this great grand master key

Great Great Grand Master Key

A key that is designed to operate all of the locks that are within the domains of two or more great grand master keys

Great Great Great Grand Master Key

A key that is designed to operate all of the locks that are within the domains of two or more great great grand master keys

Grip Handle

Style of entry lock that has a handle


A flexible loop, such as a ring made of rubber

Grommeted Padlock

A padlock that has a grommet around its case or body, to protect the finish of the door on which it is installed, and to decrease the noise created when the padlock strikes the door


1. Milled-out areas or the blade or bit of a key. 2. Broached-out or hollow areas in the keyway of a lock

Ground Wire

An electrical conductor that leads from a device to an earth ground connection


Part of terminology to indicate the different classifications for combination locks

Guard Bar

A series of two or more cross bars generally fastened to a common back plate to ensure protection of glass or screen in a door

Guard Key

The key retained by the bank which preps a series of locks in the fault. A renter's key will not work unless the guard key is used. Also known as a Preparatory Key

Guard Lever Pack

Set of levers used in a safe deposit box lock which are operated using the guard key

Guest Room Key

A single key that operates the lock in an individual room only


The parts of a duplicating key machine which follows the cuts in a pattern key or template. Also known as a Stylus or Copy Dog

Guide Lines

Chalk lines on glass which outline the foil pattern


H–Go to Top

Half-Moon Plates

See Anti-Drill Lunes

Half-Mortise Lock

A type of lock which requires partial removal of the material on which it is installed, as in the case of many desk drawer locks

Half Glass Door (Design G)

A design of door having class in upper portion only

Halogen-Type Otoscope

A viewing instrument which has an extremely bright source. The otoscope is designed to view the interior of locks


Defines the pivot location or the direction of movement. Certain conventions have been set up and used by the door industry

Hand Change Combination Lock

A type of combination lock that the combination is changed by taking the lock apart and moving certain parts. The lock is then reassembled

Hand Scan

A technique for biometric identification that measures three-dimensional hand geometry - the shape of the fingers and the thickness of the hand


Depicts the direction a door swings, i.e. from left or from the right,/p>

Hand Held Code Key Cutter

A hand operated key origination machine. This type of code machine is used to cut first keys when their depths and spacings are known

Handicapped Hardware

Specifically designed hardware that meets the ADA requirements


There are safe handles, lever handles and door (Grip) handles

Hand of Combination Lock

The orientation fo the combination lock within its mounting. The hand is indicated by the location of the combination bolt lock. As viewed from the rear of the lock. There are four positions: Vertical Up, Vertical Down, Right Hand, and Left Hand

Hand of Doors

Doors open in different directions, and to simplify non-reversible hardware such as locks, the opening of a door and the direction in which it opens that has been standardized. There are locks that specify either right or left hand opening

Hand of Lock

Refers to the adaptability of the lock to function on left or right hand doors


This refers to heat tempered steel. The steel is heated to a predetermined temperature and then quenched in oil or water for rapid cooling. The finished products are used on surfaces which require additional protection

Hardened Cylinder Ring Insert

A piece of hardened material which is placed inside a cylinder ring, to provide protection for the extended portion of the lock cylinder

Hard Plate

Any of a variety of drill resistant metals which are positioned between the safe door and the lock to prevent forced entry

Hard Wire

An alarm system where the components are connected with wire

Harmon Hinge

A hinge designed to swing a door into a pocket at a right angle with the frame


A fastening device consisting of a loop and a slotted hinge plate, normally secured with a padlock


A padlock permanently attached to a hasp

Hasp and Staple

A special type of hasp which has two or more metal plates which are interconnected with staple type metal strips. The hasp and staple style of hasp has more flexible applications than the standard hasp


The main extrusion that forms the top structure of an automatic door and which contains the controls and operators

Heel-And-Toe Locking Padlock

A type of padlock that locks the shackle both at its free end and at the end where the shackle meets the lock body

Heel of a Padlock

The end of the shackle on a padlock which is not removable from the case

Hertz (Hz)

The international unit of frequency equal to one cycle per second; named after the German physicist Heinrich Rudolph Hertz (1857-1894)

Hex Key

A hexagonal wrench used for driving certain types of screws and other fasteners. Also known as an Allen Wrench

High Security Locks

Locks that are designed to resist unauthorized entry and to provide a significant amount of key control

High Security Cylinder Cover

A thick, heavy piece of metal having a small hole in it, which is installed over the outside of a lock cylinder, so as to leave only the cylinder plug visible. The purpose of the cover is to protect the lock cylinder from forcible attack

High Shoulder

A style of padlock where the legs of the shackle slide into raised portions of the padlock body when locked. This style of padlock is more secure since the shackle is less accessible


Two plates pined together by a pin and attached to a door and its frame whereby a door is supported and is enabled to swing or move

Hinge Filler Plate

A plate installed in hinge cutout when hinge is not required

Hinge Jamb

A vertical piece of a door frame prepared for installation of hinges

Hinge Stile (of a door)

The stile to which the hinges are applied as distinguished from the lock stile

Hinged Latch Bolt

See Swinging Latch Bolt

Holdback Cam

A free rotating cam on the rear of a mortise cylinder. The cam is controlled by the retainer and its direction is limited by a pin positioned for either LH or RH applications

Hold Open

Function of a door closer, which enables the closer to hold the door in the open position usually at a point of maximum opening

Hold-Open Time

The time a door remains fully open after loss of detection

Hold-Up Alarm Trip Cylinder

A type of cylinder, usually of the pin-tumbler type, that can be operated by either of two keys. One of the keys only opens the lock; the other key opens the lock, and at the same time, activates a hold-up alarm

Hole Filler Plates

Metal plates designed to convert a cross bore opening in a door to a different application

Hole Saw

A tool used in the chuck of a drill motor, in order to cut a circular hole in wood, metal, or similar materials. The hole saw removes only a thin ring of material, producing a hole and a cylindrical plug

Hollow Core Door

A door whose interior is empty except for rails which hold the two outer sheets together

Hollywood Door

See Dutch Door


A wiring method in which each device has a separate wiring run to the control panel


Locking mechanism for sliding doors. Often used on sliding aluminum entry doors

Hook Pick

A type of pick that has a curved end, used to reach a short tumbler that is behind a longer one

Horizontal Spring Hinge

A spring hinge mortised horizontally into the bottom rail of a door and fastened to the floor and head frame with pivots


The cylindrical portion of the safe deposit lock horn plate surrounding the plug. Also known as a Nose or Nozzle

Horn Plate

The cover which secures the lock components in a safe deposit box lock case. There are single and double horn plates

Horseshoe Lock

A very large padlock with a U-shaped shackle, used to secure a bicycle or motorcycle

Host Computer

A computer that primarily provides services such as computation, data base access, or special programs and/or services


Homeland Security Presidential Directive


Homeland Security Presidential Directive calling for a mandatory government-wide standard for secure and reliable forms of ID issued by the federal government for access to federally controlled facilities and networks

Hotel Grand Master Key

A single key that operates all of the locks throughout the hotel, with the exception of the privacy doors

Housekeeper's Key

In a hotel or motel lock system, a master key or grand master key that operates the lock on two or more different groups of guest rooms


Casing which contains all internal lock parts. Also known as a Case

Housing Wrench

Tool used to tighten and loosen certain styles of interchangeable core mortise cylinders


The part of a lock through which the spindle passes to actuate the mechanism


A spring fitted to the hub of a lock to restore it to its normal position after having been actuated


I–Go to Top


Acronym for Integrated Circuit. A type of solid stated electronic component used in sensors and controls. Sometimes referred to as a “chip”

I.C. Core

See Interchangeable Core


Abbreviation for Inner Diameter

I/O Input/output


A microchip similar to those used in smart cards but housed in a round stainless steel button about a half inch in diameter, which can be attached to a key fob or jewelry. iButtons are extremely rugged, but are not available with RFID technology for contactless use


International Foundation for Protection Officers. A non-profit organization founded for the purpose of standardized training and certification of protection officers. Its Security Supervisor Training Manual is a reference guide for protection officers and their employers

Impressioning Plate

Metal plate with five or more openings. These openings are designed to secure door, deck, and assorted cam locks in order to impression

Impression Marks

Indentations made by the tumblers on the key blank blade when the proper pressure is exerted. Impression marks are used to determine the depths of cut in order to originate a key

Impression System

A means for fitting a first key to a lock. Impressioning requires the use of a key blank, a pair of locking pliers, and a file to make the key

Impression Tool

A handle for the key blank which is being impressioned. Tools include specialized impressioning tools and locking pliers

Inactive Door (or leaf)

That leaf of a pair of doors that does not contain a lock, but is bolted when closed, and to which the strike is fastened to receive the latch or bolt of the active door


The measurement of the smallest possible difference between two cuts in a key of a given lock. This would be represented by the difference between a number 3 cut and a number 4 cut, or between a number 8 cut and a number 9 cut. The actual distance might be 0.015 inch, or 0.020 inch, or 0.0125 inch, and so on

Incrementing A Key

The process of changing the combination of a key by altering a cut, one increment of depth at a time

In-Cylinder Doorway Viewer

A type of doorway viewer that has its outside parts mounted inside a rim cylinder


A line or mark with which the numbers are lined up, when dialling the combination of a lock


1. A device used in connection with locks to indicate a variety of situations including locked, occupied, etc. 2. A button inserted into a safe deposit lock plug keyway to indicate unpaid rent or an unrented box. It also prevents key insertion

Indicator Button

A device used in connection with a hotel lock to indicate whether or not the room is occupied


An influence exerted by a charged body or by a magnetic field on neighbouring bodies without apparent communication; electrifying, magnetizing, or inducing voltage by exposure to a field

Indicator Pin

In a key-in-knob lock of the hotel or motel function, a pin which, when protruding from the face of the cylinder plug, indicates the fact that the normal keys will not operate the lock at the time in question

Individual Cut

A cut that occurs in the combination of an individual key in a master key system

Individual Key Section

A key section whose key blank will enter only those cylinder plugs that have a key slot or keyway specifically designed to accept that key blank

Infrared Filter

Filter used to make light beam in photoelectric system invisible to the human eye

Infrared Sensors

Sensors designed to operate within the range of invisible radiation wavelengths. There are active, beam, illuminator, and passive infrared sensors

Infrared Shadow Card

A type of access control card that has a bar code sandwiched between two layers of plastic. The reader passes infrared light through the card, and the shadow of the bar code is read by sensors on the other side


Free access inside from the outside


Signal used to temporarily control alarm from activating. A purpose to inhibit an alarm system is to permit authorized entry into an area

Inner Bushing

Part of a plug and inner bushing assembly of a tubular lock that contains the tumbler holes and the top tumblers

Inner Spindle Assembly

A component of the manipulation proof series. It connects with the knob to actuate the cam slide


The initial surge of current through a load when power is first applied. Lamp loads, inductive motors, solenoids and capacitive load types all have inrush or surge currents higher than the normal running or steady state currents. Resistive loads, such as heater elements, have no inrush


Signal used to temporarily control alarm from activating. A purpose to inhibit an alarm system is to permit authorized entry into an area

Inner Bushing

Part of a plug and inner bushing assembly of a tubular lock that contains the tumbler holes and the top tumblers

Inner Spindle Assembly

A component of the manipulation proof series. It connects with the knob to actuate the cam slide


The portion of the construction master key which remains in the cylinder. The insert is removed using an extractor key. There are pin tumbler and wafer tumbler cylinder inserts

Installation Kits

The tools necessary as determined by the product manufacturer or company selling the installation kit to install said product

Insulated Glass (Double Pane)

Glass panes separated by air or gas. The air/gas is trapped between the two pieces of glass and acts as an insulator


A material which does not readily conduct electricity. The coating on wire is an insulator which prevent wires from "touching" each other electrically


An insulator is just the opposite of a conductor; it offers very large opposition to current flow. For example, rubber, glass, paper, air, and varnish are good insulators

Integral (locks and latches)

A term used to describe a type of mortise lock having cylinder in the knob


A condition in a master key system whereby a key operates a lock other than the one or ones it is intended. This is referred to as Crosskeying

Interchangeable Core (IC)

Unlike a standard key cylinder, which is accessible for combinating only via locking device disassembly, an interchangeable mechanism relies upon a specialized "control" key for insertion and extraction of the essential (or "core") combinating components


A system of multiple doors with controlled interaction. Interlocks are also known as lighttraps, airtraps, mantraps and sally-ports (See safety interlock, security interlock)

Interlocking Pin Tumblers

These high security, notched tumbler, master, and driver pins are designed to align for detachment from each other when the proper angle cut key is inserted. This enabled the plug to rotate. The angled cuts in the key rotate the pins back to the attachment position when the key is removed from the plug

Interlocking Pin Tumbler Cylinder

High security pin tumbler cylinder of a specific design to accommodate specialized notched pins. The cylinder plug has six circular grooves, central to the tumbler pin holes. See also Interlocking Pin Tumblers

Intermediate Sleeve

The sleeve adjacent to the inner bushing which contains the mastered tumblers. Part of the sleeve in a master keyed tubular lock

Intermittent Duty

A solenoid designed to be energized for short periods of time. Continuous operation may damage an intermittent duty solenoid

Internal Relocking Device

A relocking device that is built into the inside of the case of a combination lock

Internal Set Screw

In certain removable-core mortise cylinders, a screw that is only accessible when the core is removed, and which can be used to hold the cylinder in a mortise lock

Interstitial Cuts

Cuts that are made in the spaces between the normal cuts of a key

Intrusion Alarm

See Burglar Alarm

Intrusion Detector

Any contact or foil which is connected into the protective circuit. The detectors open the circuit when a break in occurs

Intrusion Sensors

Sensors designed to detect unauthorized entry. There are interior and exterior intrusion sensors


An electrical product which converts low voltage DC to high voltage AC

Invisible Hinge

A hinge so constructed that no parts are exposed when the door is closed

Iris Scan

A technique for biometric identification that maps the pattern of colors in the iris of the eye


A series of international vendor independent standards for proximity RFID that establishes guidelines for two types of smart cards (A & B). The most common application requires a read within 4 inches of the reader and includes Classic MIFARE, EV1, DESFire and PIV


A series of international vendor independent standards for vicinity RFID that establishes guidelines for smart cards that can read up to 1.5 meters


J–Go to Top


A vertical piece of a door frame assembly, adjacent to wall

Jamb Depth (Frame Profile)

The overall width of frame profile - face to face dimension


1. A type of tool which is used for prying objects apart, such as in prying a door away from a frame. 2. To pry apart by using a jimmy

Jimmy Resistant Lock

Type of lock that has a vertical movement in the bolt to resist prying the door away from the jamb to bypass the bolt. The bolt, in the locked position, is surrounded by a sectional hollow strike


K–Go to Top


Abbreviation for Keyed Alike


Abbreviation for Keyed Different


See Strike


A key is an instrument for operating a lock by setting the tumblers in the proper position. It can be removed for carrying, but must be inserted and used in the proper manner in the lock for both unlocking and locking the lock mechanism

Key Accessories

Any of a variety of products related to keys. These include key chains, holders, rings, clips, etc.

Key Blank

A coined and blade broached slug prior to having cuts applied. A finished but uncut key

Key Change

The combination of cuts in a key that enable it to operate the lock for which intended

Key Change Wheel

Combination lock wheel whose individual combination can be changed using a key. Normally there is a slot in the lock case permitting the combination to be changed without having to open the lid

Key Changeable Combination Lock

A combination lock designed to have the combination changed by using a special key without having to disassemble the lock

Key Code

A line of numbers and/or letters which enables the manufacturer or locksmith to originate a key without having a sample

Key Control

The lock manufacturers, distributors, and/or locksmith’s ability to limit the unauthorized duplication of keys which can operate their locks. Some methods of key control include: restricted keyways, unique keys which are too complicated to duplicate and legal protection which restricts unauthorized manufacture of key blanks

Key Cutter

An individual who duplicates keys and may provide some locksmith services

Key Gauge

Metal plate with specific depth measurements cut out. These plates are used to decode the depths of cut in a key

Key Locking Dial

A dial that can be locked with a key to prevent rotation

Key Locking Dial Ring

A dial ring containing a key lock to lock dial and prevent rotation

Key Lock Switch

An electrical switch that can only be operated by a key. See also Switch Lock

Key Machine

A manual or powered machine designed to remove material from the blade of a key blank to originate or duplicate a key. There are a number of different types and styles of key machines

Key Override

The ability of a mechanical key to operate an electronic lock at any time

Key Picking

The technique of picking a single throw wafer lock using a key blank

Key Pilot

Guide for the key to help it slide easily into the lock. The pilot might be grooved at the keyway entrance or have a contoured shape to the face plate

Key Plate

A small plate or escutcheon having only a keyhold (See Drop Escutcheon)

Key Profile

See Key Section

Key Reading

Determining the depths of cuts on a key in order to originate a new key using the determined depths

Key Records

Documents used to indicate all pertinent information for keying systems. Key records contain at least the identification of the end user, the bitting list, key bitting array, cylinder location schematic, names of persons who can receive duplicate keys, names of persons who control master keys, and number of keys per cylinder issued

Key Removable Cylinder

A lock cylinder similar in concept to the removable core and interchangeable core cylinder. In some types of key-removable cylinders, the inner part of containing all the tumblers and springs and the housing has a portion of the face plate of the knob lock or dead bolt

Key Retaining

The function of a lock that allows the key to be removed in one position only, usually in the locked position

Key Retention

The function in which a lock must be locked before the key can be removed. Also known as Keystop

Key Ring

A metallic ring that is used to keep a number of keys together. There are give away key rings, hinged rings, split rings, etc.

Key Section

The cross sectional shape of the blade of a key blank, made up of ridges (or lands) and grooves. The key section as displayed in a key blank catalog is generally viewed from bow towards the tip of the key blank. The shape of the key's section determines the keyways it can enter

Key Side

A reference point used to determine outside of door - sometimes required for handing or determination fo secure side of glass bead or louvers

Key Slot

The slot in a cylinder plug, designed to accept a key of a certain cross section. Also known as Keyway

Key Symbol

Character designation used for each key combination in the standard key coding system. A matching symbol is used to identify the compatible lock. For example, AA1. Also known as Keying Symbol

Key Tag

A metal or paper tag that can be maintained with a key to identify the keys location or any other information

Key Trap Cylinder

A lock cylinder or core specifically designed to trap a key after an attempt has been made to rotate the plug

Key Vice

The part of a key cutting machine which secures the key during the origination or duplication

Key fob

Specific form factor of credential that generally refers to a hard plastic disk that is carried on a key chain


The opening in a lock to receive a key (usually a bit key)

Keyhole Lock

A small pin tumbler lock that can be inserted into the keyhole of a bit key lock, in order to prevent the bit key from being inserted


Combination specifications for a cylinder or group of cylinders in order to control access

Keying Kit

A container which has a number of compartments that hold an assortment of tumblers, springs, and other parts necessary to combinate a lock cylinder

Keying Levels

Tumbler type cylinders offer the possibility of very complex arrangements. These are the basic terms: A. Individual Key - A key for a single cylinder. Also known as a Change Key B. Keyed Alike - All cylinders may be operated by the same key (not to be confused with Master Keyed) C. Keyed Different - A different key operates each cylinder in a group of cylinders D. Master Key - A key to operate a group of cylinders, each of which may be set to a different change key E. Master Keyed - All cylinders in a group can be operated by one master key, although all cylinders may be keyed differently (not to be confused with Keyed Alike) F. Maison Keyed - All change and master keys will operate this cylinder G. Keyed-to-Pass - Denotes a cylinder set to accept a limited number of different change and/or master keys

Keying A Lock

The way in which a lock is set to be operated by one or more keys

Key-In-Knob Lock

A lockset having the cylinders contained in the knob. Also known as a cylindrical lock

Keyless Lock

1. A lock which operates either by combination or electronically, which does not require a key to operate. 2. A lock which is designed to act as a sealing mechanism, so that once it has been locked, it can only be opened by destruction of the lock


A protrusion that prevents a key from moving past a particular point on a locking device


The aperture in lock cylinders that receives the key and closely engages with it throughout its length

Keyed Alike (KA)

A keying option which allows for any number of cylinders to operate by the same key

Keyed Different

Two or more lock cylinders with different tumbler arrangements and each using its own key. Abbreviated as KD

Kick Down Holder

A type of door stop that kicks down to hold the door open; locks in the up position to allow the door to open freely

Kick Plate

A protective plate applied on the lower rail of the door to prevent the door from being marred

Knife Edge A Key Blank

To file the working edge of a key blank to a very thin, tapered shape. This is sometimes done in order to make it easier to use the key blank in the impressioning of a lock


1. A projecting grip, usually spherical in shape designed to retract the locking mechanism. 2. Component of the manipulation proof series. It is connected with the inner spindle assembly; when turned actuates the cam side

Knob Lock

1. A type of door lock which has the lock cylinder mounted into the knob or knobs. 2. A type of lock which has a knob or knobs among its component parts

Knob Retainer

A lock part, usually in the form of a spring loaded plunger, which is used to secure a knob onto its spindle

Knob Shank

The projecting stem of a knob into which the spindle is fastened

Knob Spindle

A type of lock part which is used to transmit the motion from the knob to the locking mechanism. There are swivel straight, and two piece split spindles. Spindles are threaded and/or have through holes to accommodate the knobs

Knob Top

That part of the knob that the hand grasps


Term used by several lock manufacturers to indicate their complete knob locks

Knocked Down (KD) Frame

A door frame furnished in three or more parts for assembly in the field


The enlarged part of a hinge into which the pin is inserted


L–Go to Top


Hardware which has successfully completed testing in order to be permitted to be installed in a fire rated opening


A network of fine wire surrounding or covering an area to be protected, such as a safe, vault, or glass panel, and connected into a closed circuit system. The network of wire is concealed by a shield such as concrete or paneling in such a manner that an attempt to break through the shield breaks the wire and initiates an alarm

Laminated Glass

A type of safety glass that holds together when shattered

Laminated Padlock

A padlock, the body of which consists of a number of fast plates, most of which (if not all) are of the same contour, super imposed and riveted or brazed together. Holes in the plates or in most of them provide spaces for the mechanism and the ends of the shackle and key


Local area network


The protruding areas of the key blade which partially determines its shape. The shape of a key blade is determined by the millings and lands


A device that secures but has no locking function. Also known as a Latch Bolt

Latch Bar

The rear end of some latch bolt designs which mounts into the retractor of the lock. The retractor pulls on the latch bar to retract the latch bolt, permitting the door to open

Latch Bolt

A lock component which projects from the assembly in an extended position, but is forced back into the lock case by end pressure or drawn back the mechanism. When the door is closed, the latch bolt engages the strike, and holds the door in the closed position

Latch Bolt Keeper

The component of an electric strike which captures the lock's latch bolt and secures the door from opening. Many latch bolt keepers are shaped to accommodate a specific shape of latch bolt

Latch Bolt Sensor

An electrical component which senses the latch bolt when it is captured in electric strikes equipped with a latch bolt sensor

Latch Front Adapter

An adapter positioned behind the strike cover plate. This using reduces the opening size to one inch wide for one inch square front latches

Latch Guard

See latch protector

Latch Mortiser

A tool used to cut out the opening in a wooden door for the latch face of a lock

Latch Prongs

The rigid legs of the latch bolt which engage the housing of the outside lock unit

Latch Protector

A piece of hardware (attached to door) that completely covers the latch area protecting the latch bolt from prying and shimming. Also known as latch guard

Latch Range

The distance between the end of the sweep range and the door closed position when adjusting a door closer. This final twelve inches or so requires additional pressure for positive latching of the lock or exit device. See also Sweep Range

Latch Retractor

A type of lock part which is used to transmit motion to the latch, in order to pull it away from the strike plate. One this occurs, the door can be opened

Lazy Cam

A cam capable of rotating against the lock's plug. This can occur even though the lock's plug is rigid


Acronym for Light Emitting Diodes. A solid state lamp commonly used as an indicator in sensors and controls

Leading Door Edge

The edge of the door opposite the hinges which opens first in a double door situation

Leading Edge

The vertical edge of the door opposite the hinge

Leaf (of a pair of doors)

One of the two doors forming a pair of doors

Left Hand Door

A door which, when viewed from the outside, has its hinges on the left hand side, and opens inward. See also Hand of Doors

Left Hand Key Slot

A key slot or keyway which, when viewed as it would appear in an installed lock, has its lowermost ridge on the left hand side of the key slot

Left Hand Reverse Bevel Door

A door which, when viewed from the outside, has its hinges on the left hand side, and opens outward. See also Bevel

Left Hand Thumb Side

The face of a key that is in contact with the thumb of the left hand of the user, when the key is held in the left hand and inserted into the lock

Letter Box Lock

A type of lock that is used on a box to which mail is delivered at a private address (not inside a post office). There are two styles of letter box lock, the pin tumbler and lever. Also known as a mail box lock

Letter Box Back Plate

A plate, similar to a letterbox plate, attached to the inside of a door to allow the passage of mail

Letter Box Plate

A date attached to the door with an opening to permit insertion of mail

Lettered Key Section

A key section which is designated by its manufacturer with one or more letters of the alphabet

Level of a Key

The position of a key in the organization of a master key system. Keys that have the higher level numbers are those which operate larger groups of locks

Levels of Security

The range of security protection, low to high, provided at concentric perimeters -the least secure at the outermost perimeter (such as entry to the building) and the most secure at the innermost perimeter (such as access to a rack)


1. The locking components in a lever lock which controls the retraction of the bolt. When the proper key has been inserted, the levers align when the key is rotated, permitting the bolt to retract. (2) Serves to retract the bolt in a combination lock when the proper combination has been aligned

Lever Actuator

An arm which extends out of the housing from a Chrysler ignition lock when a key is inserted into the keyway. This lever activates the key buzzer switch

Lever Handle

A horizontal handle for operating the bolt(s) of a lock

Lever Handle Lock

A type of lock in which the latch is retracted by turning a lever on the inside or outside of a door. The lever or levers take the place normally occupied by a knob or a pair of knobs. Specific lever handle lock designs are being required by handicap codes. Also known as a Lever Lock and a Leverset

Lever Lock

See Lever Handle Lock

Lever Operated Key Duplicating Machine

A type of key making machine in which the operator moves a lever from side to side, which in turn moves the vices in relation to the guide and the cutting wheel. Also known as a semi-automatic key duplicating machine

Lever Screw

Attaches lever to the bolt in certain styles of combination locks. The lever screw can act as a travel stop for the bolt

Lever Tumbler

Flat tumbler having a pivoted motion actuated by the turning of the key and controlling the locking function


See Lever Handle Lock

Lever Spring

A spring staked into the post end of the lever to provide directional tension on the lever or fence. Some levers and springs are die cut in one piece

Lever Stop

In a combination lock case, a molded portion of the wall which prevents the lever entering the unlocked position without the proper combination first dialled

Lift (of a Key)

Any part of the top of the key blade which raises a lever

Lift (Radius)

The concave area on the lever bottom edge which is swept by the key cut

Light Emitting Diode (LED)

A diode, a solid-state device, that gives off virtually heatless colored light when electric current is passed through it. LEDs are very efficient and long-lasting and are often used for digital readouts and annunciators. Common colors include red, green and amber

Light Intensity Cutoff

In a photoelectric alarm system, the percent reduction of light which initiates an alarm signal at the photoelectric receiver unit

Limit Arm

A device used to limit how far a panel can swing when broken out

Limited Access Cam

In certain mortise type hotel or motel function locks, a cylinder cam which is able to be rotated by the normal individual keys and master keys

Limited Access Key

In a certain type of entrapment lock system, a key which will only operate the lock at certain times when the lock has been programmed to accept that key. At other times, the limited access key will be trapped by the lock

Line Amplifier

An audio amplifier which is used to provide pre-amplification of an audio alarm signal before transmission fo the signal over an alarm line. Use of an amplifier extends the range of signal transmission

Line Drop

A voltage loss occurring between any two points in a power or transmission line. Such loss, or drop, is due to the resistance, reactance or leakage of the line

Line Resistance

The opposition to current flow offered by the conductors (interconnecting wiring) in an electrical circuit. It is analogous to water moving in a pipe. The smaller the diameter of pipe (conductor) the higher the resistance to flow, conversely, the larger the diameter of a pipe the lower the resistance. The longer the run of conductor the higher the resistance

Line Sensor (Detector)

A sensor with a detection zone which approximates a line or series of lines, such as a photoelectric sensor which senses a direct or reflected light beam

Line Supervision

Electronic protection of an alarm line accomplished by sending a continuous or coded signal through the circuit. A change in the circuit characteristics, such as a change in impedance due to the circuit's having been tampered with, will be detected by a monitor. The monitor initiates an alarm if the change exceeds a predetermined amount


A connecting plate between two moving parts


The equipment used to interconnect the locking mechanism in an automobile with the door or deck lock


When an input changes the state of an output

Lip of a Strike

The projecting part on which the latch bolt rides


Preparation in a door for view window, vision and/or glazing including glass stop and glazing bead

Lite Kit

A frame inside of a door used to hold glass in place

Live Trap

A trap in which the trap wire carries the protective circuit current


A device which uses or consumes power. The larger the load is the less the resistance or opposition to current flow for a given voltage. An electrical load converts electrical energy into some other form of energy such as heat, light, sound, mechanical energy, etc.

Local Alarm

A self contained alarm system which when activated makes a loud noise at or near the protected area and/or floods the site with light

Locating Boss

An integral part of the case used to align the lock in mounting (not used in all locks)

Location Specific Alarm System

A close range personal transmitter to receiver to control center system. Personal security for institutions and hospitals

Lock (electric)

Fail Safe - A lock that is designed to unlock in the event of a loss of power Fail Secure - A lock that is designed to remain locked in the event of a loss of power Magnetic (sometimes called Electro-Magnetic) - A lock using a magnetic coil that acts against a steel plate to lock a door Solenoid - A lock that utilizes a coil and metal plunger to physically lock and/or unlock a door

Lock Case

The housing into which all the components of a mortise lock and a combination lock are installed. Lock cases can be made of cast metal or stamped from metal plate

Lock Mechanism

The part of the lock into which the key is inserted. The lock mechanism contains the tumbler mechanism which secures and frees the locking mechanism

Lock Rail (of the door)

The horizontal member of a door intended to receive the lock case

Lock Set

A lock, complete with trim, such as knobs, escutcheons or handles

Lock Stile (of a door)

The stile to which the lock is applied as distinguished from the hinge stile

Locked On By Combination

See also Dial Ring

Locked on by Combination Index

Index mark on some combination lock dial rings. A combination dialled to this index to remove lock cover and/or change combination

Locking Dog

The part of a padlock which engages the shackle and maintains it in the locked position

Locking Lug

In an IC or RC cylinder, the part of the control sleeve that projects from the side of the core to secure the core in the cylinder housing

Locking Mechanism

Often mistaken for the lock. The locking mechanism is the actual part which stops access. This can include the latch and/or the bolt

Look Out Ball

In a lock of the hotel or motel function, a ball bearing that projects into the side of the key slot, in order to prevent the normal individual or master keys from being inserted into the cylinder plug

Lock Out Key

In some hotel or motel lock systems, a key (usually a small, flat spanner key) which is used to activate a device in the guest room lock, in order to prevent the normal individual and master keys from operating the lock. This key can be used by the hotel manager to make certain that a guest must first go to the manager, before being able to gain access to the guest room

Lock Out Plug

A piece of metal which can be inserted into the key slot or keyhole of a lock, in order to prevent the normal keys from entering the lock. The lockout plug normally has a vertical end to become bound against the pins

Lock Out Plug Extractor

A tool that can be used to remove a lock out plug from the key slow or keyhole of a lock

Lockout / Cutoff

Either a function or a device. To “lockout” or cutoff is to disconnect or disable a device

Lock Pick

Tools or instruments made for the purpose of operating a lock into a locked or unlocked condition by means other than the specifically planned key

Lock Picking

The process of operating a lock into a locked or unlocked condition by means other than the specifically planned key or keys, said means being manipulated within the lock in lieu of said operating key or keys

Lock Retainer

A component, usually a metallic plate or pin used to secure the lock mechanism into a housing or locking mechanism


A lock complete with handles, trim, etc. A ready to install lock requiring now additional parts


An individual with the ability to key locks, repair locks, install locks, and bypass/neutralize locks


A type of switch which is secured by a lock. Also known as a Key Lock Switch

Logic Circuit Lock

An electronic lock in which the key is a circuit board that can be identified by the electronic apparatus in the lock


The action of slipping or shimming a spring bolt with a thing piece of celluloid or metal


An electric circuit consisting of several elements, usually switches, connected in series

Loose Joint Hinge

A hinge having but two knuckles; the pin is fastened permanently to one knuckle, the other contains the pinhole, whereby the two parts of the hinge can be disengaged by lifting. These hinges are handed

Loose Pin Hinge

A hinge having a removable pin to permit the two parts of the hinge to be separated


An opening in a door with a series of slats or blades to allow passage of air

Low Energy and Power Assist Doors

Swinging doors that meet the requirements of ANSI/BHMA A156.19

Low Voltage

Electrical current less than 120 volts. The common low voltages are 12, 24, and 48


M–Go to Top


A defined set of actions or commands that will be executed based on a trigger event

Magnetic Catch

A cupboard catch that uses a magnet to hold the door closed

Magnetic Sensor

A solid-state switch that turns on and off when a magnetic field is passed in front of it

Magnetic Stripe Card

A type of access control card that uses a magnetic strip to store information; read by inserting or swiping through a reader

Magstripe Card

See Magnetic Stripe Card

Manageable Device

Able to be monitored and controlled remotely. Manageable access control devices can communicate with a remote management system for monitoring (who’s coming and going and when), control (configuring the device to allow access to certain people at certain times), and alarm (notification of repeated unsuccessful access attempts or device failure)


An airlock-style arrangement having secured doors for entry and exit, with room for only one person between the doors. It is a solution to the security loophole called piggybacking or tailgating, in which an unauthorized person freely passes a security checkpoint by following an authorized person through an open door


Hiding or suppressing alarms which do not need to be viewed

Masonry Frame

A frame installed in a new or existing masonry or block opening

Master Key

Operates any quantity of cylinders of different individual key changes


An arrangement of cylinders having individual key changes, which permits them all to be operated by a simple key called a master key

Masterkey System

An arrangement of cylinders having individual key changes, which permits them all to be operated by one key, called a master key


A prediction of the time interval between system failures. Should be measured in thousands of hours/possibly years


A contactless and dual smart card chip technology produced by NXP that is fully compliant with ISO-14443

Mission Critical Facility

A facility that must operate 24/7/365 regardless of availability of power/water/fuel/etc. Examples would be corporate data center, 911 dispatch, military facilities

Mono Lock

See Preassembled Lock

Mop Plate

A narrow plate similar to a kick plate, of sufficient height to protect against the swish of the mop


A cavity made to receive a lock or other hardware; also the act of making such a cavity

Mortise Bolt

A door bolt designed to be mortised into a door rather than applied to its surface

Mortise Cylinder

Screw in cylinder with a cam tailpiece

Mortise Exit Device

An exit device with the lock mechanism installed into a mortise provided in the edge of a door. Mortise exit devices can be either Panic or Fire Exit Hardware

Mortise Lock/Latch

A lock designed to be installed in a mortise rather than applied to the door's surface

Mortise Lock Prep

Cutout in the edge of a door for mortise lock. Also known as mortise lock prep


A vertical member in an opening for two doors permitting each door to be operated and latched independently. The mullion may be removable or fixed


An instrument that combines several functions; usually resistance measurement, voltage measurement, and current measurement. This instrument is commonly called a VOM or OHM meter


A vertical or horizontal member in a door leaf, other than the top and bottom members

Multi-Technology Credential

A credential that contains two or more technologies (i.e. proximity, smart card, magnetic stripe)

Multi-Technology Reader

A reader with the capability to read two or more card technologies (i.e. proximity, smart card, magnetic stripe)


See silencer


N–Go to Top

Narrow Lite Door (Design NV)

Design of door with narrow rectangular lite at lock stile of door


Network-Critical Physical Infrastructure. Elements of a data center’s physical infrastructure (as distinguished from IT infrastructure such as routers and storage managers) that contribute directly to availability by ensuring uninterrupted operation. NCPI includes power, cooling, fire suppression, and physical security


National Electrical Code

Need to Know

A very high level of security, with access restricted to people who have a specific, immediate need to be in the secured area (for access to particular data, for example), with access only allowed for the time period during which that need exists


Network interface card


An auxiliary lock having a spring latch bolt and functioning independently of, and providing additional security to, the regular lock of the door


Normally open/normally closed, refers to the normal circuit state of a switch/relay

Non-Extended Bypass

The alarm sounds if the door switch (or bar switch) is opened in the armed condition. The key is required to reset the alarm. If the door is open at the end of the arming delay mode, the device will sound

Non Removable Pin Hinge (NRP)

A hinge with a set screw in its barrel; to prevent the removing of hinge pin. Set screw is not accessible when door is closed. Used with outswinging exterior doors


O–Go to Top


Abbreviation for Outer Diameter


Unit of electrical resistance. One OHM is the resistance which allows one ampere of current to flow through a conductor at one volt

Ohm’s Law

Voltage = Current x Resistance

Olive Knuckle Hinge

A paumelle hinge with knuckles forming an oval shape

Overhead Concealed (O.H.C.)

A swinging door header that is above the door and between the jambs, as opposed to a surface mounted header

P–Go to Top


Personal Access Code. Another name for PIN (Personal Identification Number) - a code or password that identifies a user at an access point


Abbreviation for "Parallel Arm Closer Reinforcement" - Welded-in reinforcement, in frame head, for mounting of door closer

Pair Frame

A door frame, to accommodate two doors or a pair

Pair of Doors

See double doors

Panic Bar

See exit device

Panic Exit Device

See exit device

Panic Hardware

A door latching assembly incorporating an actuating member usually called actuating bar which releases the latch bolt(s) upon the application of force in the direction of exit travel Panic Hardware/Exit Device Types (according to ANSI/BHMA)

Type 1: Rim Exit Device

Type 2: Surface Vertical Rod Exit Device

Type 3: Mortise Exit Device

Type 4: Narrow Stile Rim Exit Device

Type 5: Narrow Stile Surface Vertical Rod Exit Device

Type 6: Narrow Stile Concealed Vertical Rod Exit Device

Type 7: Wood Door Concealed Vertical Rod Exit Device

Type 8: Metal Door Concealed Vertical Rod Exit Device

Type 9: Combination Rim and Surface Vertical Rod Exit Device

Type 10: Narrow Stile Mortise Exit Device

Type 11: Combination Mortise and Surface Vertical Rod Exit Device

Type 12: Combination Mortise and Concealed Vertical Rod Exit Device

Type 21A: Door Coordinator with Override Feature

Type 21B: Door Coordinator without Override Feature

Type 22: Removable Mullion

Type 23: Concealed Automatic Latching Two Point Bolts

Type 24: Surface Automatic Latching Two Point Bolts

Type 25: Automatic Extension Flush Bolt

Type 27: Self-latching Extension Flush Bolt Set

Type 28: Rim Exit Device incorporating a Dead Bolt

Panic Hardware/Exit Device Functions (according to ANSI/BHMA)

01: Exit only, no trim or blank escutcheon

02: Entrance by trim when actuating bar is locked down

03: Entrance by trim when latch bolt is released by key. Key removable only when locked

04: Entrance by trim when latch bolt is released by key or set in a retracted position by key

05: Entrance by thumb piece. Key locks or unlocks by thumb piece

06: Entrance by thumb piece only when released by key. Key removable only when locked

07: Entrance by thumb piece. Inside or outside key locks or unlocks thumb piece. Outside key releases latch

08: Entrance by knob or lever. Key locks or unlocks knob or lever

09: Entrance by knob or lever only when released by key. Key removable only when locked

10: Entrance by knob or lever. Inside or outside key locks or unlocks knob or lever. Outside key releases latch

11: Entrance by control turnpiece. Key locks or unlocks control

12: Entrance by control turnpiece only when released by turning key. Key removable only when locked

13: Entrance by key or combination lock

14: Entrance by trim when latch bolt is released by knob or lever. Always active, no cylinder

15: Entrance by trim when latch is released by thumb piece. Thumb piece always active, no cylinder

16: Entrance by trim when latch is released by control turnpiece. Turnpiece always active, no cylinder

17: Entrance by control turnpiece. Inside or outside key locks or unlocks turnpiece. Outside key releases latch


A term used in connection with cylinder plugs having projections on the sides of the keyway that extend beyond the vertical center line of the keyway

Passage Function

Doors do not lock. There is no key cylinder and no means to lock a passage set. BHMA function 14


A style of hinge embodying a single pint of the pivot type, generally of modern, or streamlined design

Peanut Cylinder

A type of pin tumbler mortise cylinder which is much smaller in diameter than a standard size cylinder. The peanut cylinder is 3/4" in diameter and the standard cylinder is 15/16" in diameter. This type of cylinder is often used in aluminum-and-glass type storefronts

Physical Security

Protecting physical facilities from accidents or sabotage caused by the presence of unauthorized or ill-intentioned people. A physical security system includes access control devices for automated screening at entry points, plus a sensor-based alarm system. Additional protection may include camera surveillance and security guards

Piano Hinge

See Continuous Hinge


The security breach that occurs when an authorized person, having unlocked a door using legitimate credentials, holds the door open for an unauthorized person to follow through the checkpoint with no credentials. (See Tailgating)


A code or password that identifies a user at an access point

Pin Tumblers

Small sliding pins in a lock cylinder, working against coil springs and preventing the cylinder plug from rotating until the pins are raised to the proper alignment by bitting of key


Personal identification verification


See Door Pivot

Plug (of a cylinder)

The round part containing the keyway and rotated by the key to transmit motion to the bolt(s)

Pocket Door

A door that is prepared to slide into a pocket built in the wall

Poke Hole

See Access Hole

Potentiometer (POT)

An electronic device used to vary electrical voltage. These are present in many controls as adjustments to vary range, sensitivity, speed, or timing

Power Assist Close (P.A.C.)

A swinging door that has a spring to close the door; but, in addition, applies a low voltage to the motor to assist in closing or holding closed a door in the case of wind load or extra heavy doors. This type of control may keep a low voltage on the motor at all times, even when the door is closed. The term “power boost” is sometimes used to describe this system

Power Open - Power Close (P.O.P.C.)

A door that both opens and closes under power

Power Open - Spring Close (P.O.S.C.)

A door that opens under power but is closed by a spring

Preassembled Lock

A lock that has all the parts assembled as a unit at the factory, and when installed in a rectangular notch cut into the door edge, requires little or no disassembly

Preparatory Key

See Guard Key

Prison Lock

A heavy lock designed especially for use on jail cells

Privacy Function

Outside knob/lever locked by pushbutton on inside knob/lever. Rotating inside knob/lever or closing door releases/unlocks button. Emergency release in outside knob/lever

Proximity Credential

An access control card that has an onboard RFID transmitter/receiver, allowing it to communicate with a reader from a distance of up to one meter (3 feet). Typically 125KHz frequency

Prox Card

See Proiximity Credential

Proximity Smart Card

A smart card that has RFID technology in its chip, so that it can communicate with the reader from a distance of up to 10 cm. (4 inches). Also called a contactless smart card. Typically 13.58MHz frequency

Push Bar

A horizontal bar surface applied to a door leaf

Push Plate

A plate applied to the lock stile to protect the door against soiling and wear


Process of applying a coating/finish on a product with positive vapour


Q–Go to Top

Quadrant (Dutch Door)

A device to fasten together the upper and the lower leaves of a Dutch door


R–Go to Top


A term used to describe the abutting edges of a pair of doors or windows so shaped as to provide a tight fit. One half of the edge projects beyond the other half, usually 1/2. Also used to define that portion of a door frame into which the door fits

Rabbeted Lock/Latch

A lock in which the face conforms to the rabbet found on a rabbeted door


Abbreviation for "Regular Arm Closer Reinforcement" - Welded-in reinforcement, in frame head, for mounting of door closer

Rail (of a door)

A horizontal member that pins the stiles. May be exposed as in a paneled door, or concealed as in a flush door


A solid state electrical device that will allow current to flow in one direction. It is designed to convert AC current to DC current

Reed Switch (aka Magnetic Switch)

A switch made up of two metal reeds. This switch is closed or opened by a magnetic field. These are usually encased in either a tubular or rectangular plastic housing

Reinforcing Unit

metal box-shaped reinforcement for use in a metal door in which a bored lock is to be installed. It provides both vertical and horizontal latch support


An electro-mechanical device that enables several circuits to be switched simultaneously under the command of a single signal. There are many types and sizes. Some common ones are S.P.S.T. (Single Pole Single Throw), S.P.D.T. (Single Pole Double Throw), D.P.S.T. (Double Pole Single Throw), and D.P.D.T. (Double Pole Double Throw). Relays are rated in terms of coil voltage, contact current ratings, and contact voltage ratings

Removable Mullion

A mullion which can be temporarily taken out of opening to allow the passage of large objects through the opening


An electronic component that resists current flow. There are various types and power ratings. The value is expressed in OHMs and the rating in watts. They also have tolerances

Retinal Scan

A technique for biometric identification that maps the pattern of blood vessels in the retina of the eye


The return leg at the back of frame profile


The distance from the surface of a swinging door leaf to the mounting surface of the operator

Reverse Bevel

See Bevel

Reversible Lock

A lock which, by reversing the latch bolt, may be used by any hand. On certain types of locks, other parts must also be changed


A request-to-exit device used as an input on an access control system to signal authorized egress


Radio frequency identification. Communication between card and reader without physical contact. RFID technology is what makes proximity cards, vicinity cards, and contactless smart cards work. The RFID chip is powered by an electromagnetic field from the reader

Rigid Cam

See Fixed Cam

Rigid Lock

See Preassembled Lock


A term indicating articles of hardware designed for application to the surface of doors and windows

Rim Cylinder

Cylinder often used with exit devices because of long cut able tailpiece for outside key control trim that inserts into device

Rim Exit Device

An exit device with the latching mechanism applied to the face of a door. Rim exit devices can be either Panic or Fire Exit Hardware

Roller Latch

A friction door latch employing a roller latch head under spring tension, which engages a strike having a recess formed to receive the roller

Roller Strike

A strike having a rolling member at the point of latch bolt contact to minimize friction


A trim plate attached to the door under the knob. It sometimes acts as a knob bearing

Rough Opening

The size of a wall opening into which frame is to be installed

Rounded Front

A lock or bolt front conforming to the rounded edge of a double acting door. The standard radius is 4" (101.6 mm)


S–Go to Top

Safety Interlock

A multidoor system in which all doors are normally closed and unlocked. Opening any door will lock all other doors

Sash Balance

A spring device used to counterbalance the weight of a window sash or other vertical sliding part

Sash Center

A pivoted support for transom or sash and comprised of two parts, one of which contains a pivot, the other a socket for the pivot

Sash Chain

A metal chain adapted for use with sliding sash, attached to the sash and to the counterbalancing sash weight

Sash Cord

Cord or rope used similarly to sash chain and in place of chain

Sash Cord Iron

A small metal holder inserted in the edge of the sash, to which sash cord or sash chain is attached

Sash Fast

A fastener attached to the meeting rail of double-hung windows

Sash Lock

A sash fast with a locking de vice controlled by a key

Sash Pole

A wood or metal pole to which a sash pole hook is attached

Sash Pole Hook

A metal hook attached to a wooden or metal pole used to lower or raise a transom or sash beyond hand reach

Sash Pulley

A pulley mortised into the frame of a double-hung sash frame over which the sash cord or sash chain passes

Sash Socket

A metal plate containing a hole or cup to receive a sash pole hook

Sash Weight

A weight used to balance sliding sash, usually of cast iron or, if conditions require, of lead

Screen Door Latch

A small locking or latching device used on screen doors and operated by a knob or a lever handle

Screwless Knob

A knob attached to a spindle by means of a special wrench as distinguished from the more commonly used side knob screw

Screwless Rose

A rose with concealed method of attachment


Software Development kit

Secret Gate Latch

A surface-applied latch operated by a concealed button or other device; usually used on office gates

Security Interlock

A multidoor system in which all doors are normally closed and locked. Opening any door will will disable the door releases of all other doors


When a door must close on its own, with the assistance of closing hardware. Properly installed door closers or spring hinges will make a door self-closing. Self-closing doors are required for fire rated openings

Self-Latching Flush Bolt

A flush mounted locking device for the inactive leaf of a pair of doors that latches automatically and unlatches manually

Shank (of a knob)

The projecting stem of a knob into which the spindle is fastened

Shelf Pin

A pin for supporting a shelf; also called a shelf support or shelf rest


Length of time that an input will be masked

Shutter Operator

A device incorporating a hinge and a method of opening or closing a shutter by means of a crank or turn from inside without opening window

Shutter Worker

See Shutter Operator

Side Knob Screw

A set screw used to fasten a knob to a spindle

Sidelite Frame

The same as a borrowed lite except that it is attached to a door frame

Sight Line

The continuation of various horizontal extrusions on a door and its adjoining walls

Signal Sash Fastener

A sash fastening device to lock double-hung windows that are beyond reach from the floor. It has a ring for a sash pole hook. When locked, the ring lever is down; when the ring lever is up, it signals by its upright position that the window is unlocked


A rubber part attached to the stop on a frame to cushion the closing of a door

Sill (Frame)

The bottom horizontal piece of a borrowed lite or sidelite frame

Simultaneous Pair

Two swinging doors, side by side, in a common header, without a separator, that always operate together

Single Pole/Double Throw (SPDT)

A term used to describe a switch or relay contact form (1 form C) that has a normally open and a normally closed contact with a common connection

Single Pole/Single Throw (SPST)

A switch with only one moving and one stationary contact, available either normally open (NO) or normally closed (NC)

Single Acting Operator

An automatic door operator that moves in a single direction in the closed position and cannot move in the opposite direction

Smart Card

A type of access control card that stores information in a microchip. The chip not only stores data, but can perform computation and exchange data with the reader. It is read by touching the card to the reader so that the electrical contacts line up. See also contactless smart card

Smart Media

Small objects of any shape that contain the same type of chip used in a smart card. Smart media are typically small objects (tokens) that can be attached to a key ring or worn as jewelry

Social Engineering

The use of ordinary guile and deceit to con people into relaxing security procedures - for example, such as revealing passwords, lending keys, or opening doors


Portion of the frame between stops on a double rabbeted frame and the stop and the largest face on a single rabbeted frame

Solid-State Relay

A relay that is a solid-state switch rather than an electro-mechanical device. This type of relay requires power to perform its switching, and it has no moving parts

Spindle (of a knob)

The bar or tube connected with the knob or lever handle that passes through the hub of the lock or otherwise engages the mechanism to transmit the knob action to the bolt(s)

Split Astragal

An astragal that is split through the middle, allowing each door leaf to operate independently

Spreader Bar

Metal bars at base of welded frame to keep frame in alignment during assembly, transportation and handling - not to be used for installation

Spring Hinge

A hinge containing one or more springs to move the door into the de sired position. It may be either single or double acting

Spring Open - Power Close (S.O.P.C.)

A door that opens under spring tension and closes under power. Useful for smoke evacuation system applications

Steel Stud Anchor

A metal piece inside throat of frame used to secure frame to steel stud

Steel Window Frame

A four sided steel frame, which is glazed (has glass) but does not include a door. Also known as Borrowed Lite


Linear lengths of frame sections used for fabrication of transom/sidelite frames

Stile (of a door)

A vertical member of the door structure; each door has two, a lock stile and a hinge stile

Stop (of a frame)

The part of frame against which door closes

Stop (of a lock)

The button, or other small device, that serves to lock the latch bolt against the outside knob or thumb piece or unlock it if locked. Another type holds the bolt retracted

Store Door Handle

A heavy grip or pull mounted on sectional or elongated plates and provided with a thumb piece to operate the latch trip of a store door lock

Storeroom Function

Entrance by knob or lever only when released by key. Key removable only when locked. BHMA function 09

Strap Hinge

A surface hinge of which one or both leaves are of considerable length


A metal plate or box that is pierced or recessed to receive the bolt or latch when projected

Strike Jamb

A vertical piece of a door frame prepared for installation of lock strike

Surface Applied

A door header that is applied to the wall or frame surface


Mounted on exterior existing material/ mounted inside a wall/ header to be out of sight

Surface Hinge

One having both leaves surface applied

Swinging Latch Bolt

A bolt that is hinged to a lock front and is retracted with a swinging rather than a sliding action

Swing-side (sometimes called the Safety-side)

A term used to describe the side of a swinging door that encompasses the swing path

Switch, Maintained

A switch that, when activated, maintains its activated position until it is unactivated

Switch, momentary

A switch that, when activated, automatically returns to its original position afterwards

Swivel Spindle

A spindle having a joint midway in its length to permit the knob at one end to be made rigid by the stop works while the other end is free to operate


T–Go to Top

T Handle

A cross handle for actuating the bolt of a lock and used in place of a knob

T Hinge

A surface hinge with the short member attached to the jamb and the long member attached to the door


The security breach that occurs when an unauthorized person slips past a checkpoint undetected, by following an authorized user through an open door. (See also piggybacking)


A digital input which monitors the status of a device, typically the door of an enclosure

Tamper Resistant Screws

A type of screw which is designed to make removal using standard tools extremely difficult. Some tamper resistant screws require special tools to install

Telescoping Slider

Two or more leaves slide in the same direction to arrive at the full open position at the same time

Tempered Glass

A type of safety glass that has been treated by heat or chemicals to increase its strength. If broken, the glass breaks into small fragments instead of large, jagged pieces


In biometrics, a computed transformation of a scan - still unique to the individual but taking up much less storage. It is the template, not the raw scan, that is stored in a database of users or on the chip of a smart card, for comparison to a live scan taken at an access point

Template Hardware

A term indicating any item of hardware that is made to template; that is, exactly matching the master template drawing as to spacing of all holes and dimensions


The socket or bearing attached to an escutcheon plate in which the end of the knob shank rotates

Three-Point Lock

A device sometimes required on three-hour fire doors to lock the active leaf of a pair of doors at three points


A strip fastened to the floor beneath a door, usually required to cover the joint where two types of floor material meet

Threshold (Biometrics)

In biometrics, the user-adjustable parameter that can be used to adjust the two failure rates (false acceptance and false rejection). Since it represents “How close is close enough?” decreasing one of the failure rates automatically increases the other

Threshold Sensors

Presence sensors used to detect a person in the space between two non-overlapping zones in the threshold area

Throat (of a frame)

The opening between backbends of frame

Throw (of a deadbolt or latch bolt)

Measurement of the maximum projection when bolt is fully extended

Thumb Piece (of a handle)

The small pivoted part above the grip of a handle to be pressed by the thumb to operate a latch bolt

Time Schedules

Consists of time ranges that are associated with days of the week or holidays, and are often used with access levels or as trigger events

Timely Frame

Brand name of a prefinished steel door frame, for stud walls


A small object with a microchip that carries your personal identifying information. The token is touched to a reader, or simply brought within range if it includes RFID capability


A term usually applied to the microwave transmitter/receiver module in a microwave motion sensor


A term used to describe a device that emits energy. Usually an ultrasonic transmitter/receiver


A device that can either reduce or increase electrical voltage. In the automatic door industry, it is usually used as a method to reduce voltage


A three lead solid-state device used in electronics as either a switch or an amplifier. These can be low power units or high power units requiring heat sinks

Transom Bar

That part of a door frame that separates the top of a door or a window from the bottom of the transom

Transom Catch

A fastener applied to a transom and having a ring by which the latch bolt is retracted

Transom Chain

A short chain used to limit the opening of a transom; usually provided at each end with a plate for attachment

Transom Frame

A door frame having a panel, louver, sash or glass above door opening with or without transom bar

Transom Lift

A vertically operated device attached to a door frame and transom by which the transom may be opened or closed

Transom Panel

A panel installed in a frame above the door opening


An event or manual action that will cause another event or execution of a macro


Trim is composed of both operating and non-operating decorative elements and includes knobs, levers, pulls, roses, escutcheons, lock fronts, strikes, actuating bars, turns, thumb pieces, vertical rods, cylinder assemblies, and covers

Tubular Lock (or Latch)

A type of bored lock


A guard or obstruction that pre vents operation of a bolt except by insertion of the proper key


The component that projects or releases a bolt or latch bolt by turning. Sometimes called a turnpiece

Turn Piece

A small knob, lever or tee turn with spindle attached for operating the deadbolt of a lock or a mortise bolt

Two-Point Latch

A device sometimes required on three-hour fire doors to lock the inactive leaf of a pair of doors at top and bottom


U–Go to Top


The clearance between bottom offrame and bottom of door - The floor clearance may not be the same as the clearance between the bottom of the door and the finished floor - the floor clearance can only be determined after the finish material is in place

Unit Lock

See Preassembled Lock


A term used to describe a lock, a door closer or other device that can be used on doors of any hand without change


V–Go to Top


An acronym for the term “Volt-Ampere.” This term is used to indicate the power capacity of a transformer. For example a 40 VA transformer can supply 40 VA of power without exceeding its capacity

Vertical Rod Exit Device

An exit device with top and bottom latching mechanism, applied to the face of the door or concealed inside the door connected by rods to the actuating mechanism. Vertical rod devices are permitted to be supplied without bottom latching mechanism. Vertical rod exit devices can be either Panic or Fire Exit Hardware

Vertical Spring Pivot Hinge

A spring hinge mortised into the heel of a door and fastened to the floor and head with pivots

Vicinity Card

An access control card that has an onboard RFID transmitter/receiver, allowing it to communicate with a reader from a distance of up to one meter (3 feet)

Vision Lite (Design V)

Design of door having one small view window in upper portion only, usually square design on vertical center line of door

Voice Print

In biometrics, a digital representation of a user’s voice used for comparison with the user’s live speech at an access point

Volt/Amp (VA) rating

The product of rated input voltage multiplied by the rated current. This establishes the "apparent energy" available to accomplish work

Voltage Drop

A term used to indicate reduction of voltage through a conductor over a specified distance


W–Go to Top


Wide area network


An obstruction projecting from the lock case of side of a keyhole intended to prevent entrance or rotation of an improperly cut key


The common unit of electrical power. One watt is dissipated by a resistance of one ohm through which one ampere flows


A measure of power consumption

Wiegand Card

A type of access control card that uses embedded work-hardened wire (Wiegand wire) to hold information read by swiping it through a reader

Wire Glass

A type of glass that has a grid of mesh or thing metal wire embedded within the glass

Affiliations & Memberships:

Door Surgeon logo Bee Cool Glass Coating company logo. Lock Surgeon BBB Business Review
Member of the Associated Locksmiths of America. Member of the Professional Locksmiths Association of Alberta. Member of the Petroleum Oriented Safety Training. Member of the Alberta Association of Safety Partnerships.