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Glossary of Terms

T-Handle

(n.) A T-shaped handle assembly which may be lockable.
Source: Lock Industry Standards and Training (LIST) Council

T-Strike

(n.) A strike whose lip spans the middle portion (but not the full height) of the strike.
Source: Lock Industry Standards and Training (LIST) Council

Tactile

(adj.) Of or pertaining to a knob, lever or other device to open a door, which conveys a special sense of touch; typically used as a warning to the visually impaired of danger on the other side of the door.
Source: Lock Industry Standards and Training (LIST) Council

Tailpiece

(n.) An actuator attached to the rear of the cylinder, parallel to the plug, typically used on rim, key-in-knob or special application cylinders.
Source: Lock Industry Standards and Training (LIST) Council

Talon

(n.) The part of a lever lock bolt that is relieved to allow the key to enter and move the bolt.
Source: Lock Industry Standards and Training (LIST) Council

Tamper Resistant Fastener

(n.) Any one of several screws or nuts which have a specialized head, requiring a special-access tool for removal.
Source: Lock Industry Standards and Training (LIST) Council

Tamper Switch

(n.) A sensor that signals when someone attempts to access the mechanism of a security device.
Source: Lock Industry Standards and Training (LIST) Council

TCP

(abb.) Transmission Control Protocol
Source: Lock Industry Standards and Training (LIST) Council

TCP/IP

(n.) The system networks use to communicate with one another.
Source: Lock Industry Standards and Training (LIST) Council

Telescoping Bolt

(n.) The bolt of a locking device which extends and retracts by successive overlapping sections.
Source: Lock Industry Standards and Training (LIST) Council

Telescoping Column

(n.) A steering column adjustable for length.
Source: Lock Industry Standards and Training (LIST) Council

Template

(n.) A pattern used to mark cutout locations for hardware installation.
Source: Lock Industry Standards and Training (LIST) Council

Template Hinge

(n.) A hinge with dimensions, hole locations and tolerances which conform to ANSI standard A156.7
Source: Lock Industry Standards and Training (LIST) Council

Tension Wrench

(n.) A tool used to apply torque to a lock bolt or cylinder plug while attempting picking.
Source: Lock Industry Standards and Training (LIST) Council

Theoretical Key Changes

(n. pl.) The total possible number of different combinations available for a specific cylinder or lock mechanism.
Source: Lock Industry Standards and Training (LIST) Council

Thermal Lance

(n.) An instrument, used for cutting with a pure oxygen feed, that uses itself and the material being cut as fuel.
Source: Lock Industry Standards and Training (LIST) Council

Thermal Relocker

(n.) A relocking device which is activated by heat.
Source: Lock Industry Standards and Training (LIST) Council

Threaded Rose

(n.) A rose with an internally threaded ferrule.
Source: Lock Industry Standards and Training (LIST) Council

Three Column Progression

(n.) A process wherein key bittings are obtained by using the cut possibilities in three columns of the key bitting array.
Source: Lock Industry Standards and Training (LIST) Council

Three Pin Master Key

(n.) A master key for all combinations obtained by progressing three bitting positions.
Source: Lock Industry Standards and Training (LIST) Council

Three Point Latch

(n.) A self-latching device designed to latch a door at the top, bottom and edge.
Source: Lock Industry Standards and Training (LIST) Council

Throat Cut

(n.) The cut made into a key to bypass a throat ward.
Source: Lock Industry Standards and Training (LIST) Council

Throat Ward

(n.) An obstruction formed in a lock's case or horn at the point of key entry, which prevents key rotation.
Source: Lock Industry Standards and Training (LIST) Council

Throw

(n.) The distance a bolt or latch projects from the faceplate or case of a lock in the extended position.
Source: Lock Industry Standards and Training (LIST) Council

Throw Member

(n.) An intermediate actuator which engages the rear of the plug to transfer motion to a cam, tailpiece or other actuator.
Source: Lock Industry Standards and Training (LIST) Council

Thumb Cuffs

(n.) Restraints designed to lock on the thumbs.
Source: Lock Industry Standards and Training (LIST) Council

Thumb Index

(n.) A projection of metal on a key bow which serves as a tactile means of orienting a non reversible key for correct lock insertion.
Source: Lock Industry Standards and Training (LIST) Council

Thumb Latch

(n.) A lock with a thumbpiece to actuate the latch.
Source: Lock Industry Standards and Training (LIST) Council

Thumb Turn

(n.) A actuator which can be turned by thumb and forefinger.
Source: Lock Industry Standards and Training (LIST) Council

Thumb Turn Cylinder

(n.) A cylinder with a turn knob rather than a keyway and tumbler mechanism.
Source: Lock Industry Standards and Training (LIST) Council

Thumbpiece

(n.) A generally flat, projecting latch actuator found above a grip handle and depressed by the thumb.
Source: Lock Industry Standards and Training (LIST) Council

Tilt Column

(n.) A steering column design which permits vertical adjustment of the steering wheel.
Source: Lock Industry Standards and Training (LIST) Council

Time Delay

(n. and adj.) A feature which prevents operation until a set amount of time has elapsed. Activation normally begins when access, egress or other unlocking is desired.
Source: Lock Industry Standards and Training (LIST) Council

Time Delay Lock

(n.) A lock that has a mechanism for preventing unlocking until a specific amount of time has passed.
Source: Lock Industry Standards and Training (LIST) Council

Time Lock

(n.) A secondary device which prevents movement of a bolt or boltworks until a set amount of time has elapsed. The device is normally set or activated at the time of locking.
Source: Lock Industry Standards and Training (LIST) Council

Timing

(n.) The engagement or positioning of an assembly of internal parts so as to produce the desired sequence of engagement during operation.
Source: Lock Industry Standards and Training (LIST) Council

Tip

(n.) The portion of the key which enters the keyway first.
Source: Lock Industry Standards and Training (LIST) Council

Tip Stop

(n.) A type of stop located at or near the tip of the key.
Source: Lock Industry Standards and Training (LIST) Council

Tips & Stems

(n.) A key bow and shank that uses a detachable end with a bit(s) on it.
Source: Lock Industry Standards and Training (LIST) Council

TL-15

(n.) A U.L. rating given to a container whose door has been tested against forcible entry, with common hand tools, for a period of 15 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

TL-30

(n.) A U.L. rating given to a container whose door has been tested against forcible entry, with common hand tools and/or abrasive cutting wheels and power saws, for a period of 30 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

TMK

(abb.) Top Master Key
Source: Lock Industry Standards and Training (LIST) Council

Toe (of a Shackle)

(n.) That part of the shackle, which may be removed from the padlock body.
Source: Lock Industry Standards and Training (LIST) Council

Toggle

(n.) A pivoting one-piece stop works activator.
Source: Lock Industry Standards and Training (LIST) Council

Token

(n.) A self-contained electronic key.
Source: Lock Industry Standards and Training (LIST) Council

Tolerance

(n.) The deviation allowed from a given dimension.
Source: Lock Industry Standards and Training (LIST) Council

Tone Dialer

(n.) A telephone communication device, normally activated by an alarm, that uses a series of tones to dial a predetermined number.
Source: Lock Industry Standards and Training (LIST) Council

Top Jamb Mount

(n.) Surface application of a door closer body directly to the header.
Source: Lock Industry Standards and Training (LIST) Council

Top Master Key

(n.) The highest level master key in a master key system.
Source: Lock Industry Standards and Training (LIST) Council

Top of Blade

(n.) The bitted edge of a single bitted key.
Source: Lock Industry Standards and Training (LIST) Council

Top Pin

(n.) Usually a cylindrical shaped tumbler, usually flat on both ends and installed directly under the spring in the pin stack.
Source: Lock Industry Standards and Training (LIST) Council

Total Position Progression

(n.) A process used to obtain key bittings in a master key system wherein bittings of change keys differ from those of the top master key in all bitting positions.
Source: Lock Industry Standards and Training (LIST) Council

Touch Bar

(n.) A type of exit device actuator which typically does not pivot and retracts the bolt with a minimum of pressure.
Source: Lock Industry Standards and Training (LIST) Council

Touch Pad

(n.) 1. An exit device actuator with a paddle shape.
(n.) 2. A remote door opener activator, typically electric or electronic, which facilitates handicap access.
Source: Lock Industry Standards and Training (LIST) Council

Track

(n.) The bitting surface of a sidewinder key.
Source: Lock Industry Standards and Training (LIST) Council

Trailing Face

(n.) The door face farthest from the strike side of the jamb when the door is open.
Source: Lock Industry Standards and Training (LIST) Council

Transom Catch

(n.) A surface mounted latch, typically having an actuator operated by a long pole or an attached pull chain.
Source: Lock Industry Standards and Training (LIST) Council

Tri Spoke Handle

(n.) A safe handle that has 3 extensions off the main hub.
Source: Lock Industry Standards and Training (LIST) Council

Tri-Bolt

(adj.) Referring to a three point locking system usually found on round door safes.
Source: Lock Industry Standards and Training (LIST) Council

Trick Lock

(n.) A lock which requires successful operation of one or more moving panels, concealed buttons, etc., often in addition to normal operation by key and/or combination.
Source: Lock Industry Standards and Training (LIST) Council

Trim

(n.) Exposed components of a lockset or latchset, which allow operation, enhance appearance or provide protection.
Source: Lock Industry Standards and Training (LIST) Council

Trim Panel

(n.) The decorative and functional assembly, which covers the inside surface of a vehicle, door.
Source: Lock Industry Standards and Training (LIST) Council

Triplex Spindle

(n.) A spindle with three wedge shaped bars which spread to grip the inside of the knob shank when the knob set screw is tightened.
Source: Lock Industry Standards and Training (LIST) Council

TRTL-15x6

(n.) A U.L. rating given to a container when it has been tested against forcible entry, on all six sides, with common hand tools and/or abrasive cutting wheels, power saws, and oxy-fuel gas cutting or welding torch for a period of 15 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

TRTL-30

(n.) A U.L. rating given to a container where the door has been tested against forcible entry with common hand tools and/or abrasive cutting wheels, power saws, and oxy-fuel gas cutting or welding torch for a period of 30 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

TRTL-30x6

(n.) A U.L. rating given to a container when it has been tested against forcible entry, on all six sides, with common hand tools and/or abrasive cutting wheels, power saws, and oxy-fuel gas cutting or welding torch for a period of 30 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

TRTL-60

(n.) A U.L. rating given to a container where the door has been tested against forcible entry with common hand tools and/or abrasive cutting wheels, power saws, and oxy-fuel gas cutting or welding torch for a period of 60 man minutes.
Source: Lock Industry Standards and Training (LIST) Council

Trunk Lock

(n.) 1. A hinged strap with a staple or a lock at the end that mates with a receptacle in the trunk.
(n.) 2. A lock designed to secure the trunk of an automobile.
Source: Lock Industry Standards and Training (LIST) Council

Trunnion

(n.) The part of a lever lock that accepts the key and stabilizes it, typically a single piece or an assembly consisting of some combination of a nose, guide and foot.
Source: Lock Industry Standards and Training (LIST) Council

Try-Out Key

(n.) A manipulation key which is usually part of a set, used for a specific series, keyway, and/or brand of lock.
Source: Lock Industry Standards and Training (LIST) Council

TTL

(abb.) 1. Transistor Transistor Logic
(abb.) 2. Time To Live
Source: Lock Industry Standards and Training (LIST) Council

Tube

(n.) A hollow structure attached to the outside of a combination lock for enclosing the spindle between the lock case and the dial.
Source: Lock Industry Standards and Training (LIST) Council

Tubular Key

(n.) A key with a tubular blade. The key cuts are made into the end of the blade, around its circumference.
Source: Lock Industry Standards and Training (LIST) Council

Tubular Key Cylinder

(n.) A cylinder whose tumblers are arranged in a circle and which is operated by a tubular key.
Source: Lock Industry Standards and Training (LIST) Council

Tubular Lockset

(n.) a bored lockset whose latch or bolt locking mechanism is contained in the component installed into the edge bore.
Source: Lock Industry Standards and Training (LIST) Council

Tubular Pick

(n.) A pick designed to operate a tubular key lock.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler

(n.) A movable obstruction of varying size and configuration in a lock or cylinder which makes direct contact with the key or another tumbler and prevents an incorrect key or torque device from activating the lock or other mechanism.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler Lock

(n.) 1. Tumblers are small objects, usually made of metal that move within a block cylinder in ways that obstruct a lock’s operation until an authorized key or combination moves them into alignment. Provides more security that a ward lock. Different type of tumbler locks are: Lever Tumbler Locks, Disc Tumbler Locks and Pin Tumbler Locks.
Source: Phillips, Bill; The Complete Book of Locks and Locksmithing, fifth edition, McGraw Hill, 2001
(n.) 2. The part in a lock that releases the bolt when moved by a key.
Source: Dictionary.com

Tumbler Nest

(n.) A position within a lock designed to accept a tumbler pack, it typically includes a tumbler post and a spring rest.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler Pack

(n.) A complete set of lever tumblers for a given lock.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler Post

(n.) A rod mounted in a lever lock, upon which the pivoting ends of the tumblers are in turn mounted.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler Separator

(n.) A thin spacer placed between lever tumblers to reduce friction.
Source: Lock Industry Standards and Training (LIST) Council

Tumbler Spring

(n.) Any spring which acts directly on a tumbler.
Source: Lock Industry Standards and Training (LIST) Council

Turn

(n.) A lock, latch or exit device part which is contacted to achieve the normal operation. It may be a knob, lever or thumb turn.
Source: Lock Industry Standards and Training (LIST) Council

Turn Disk

(n.) A disk shaped component with a cam actuated by a thumb turn, normally used in a mortise lock.
Source: Lock Industry Standards and Training (LIST) Council

Twisting Tumbler

(n.) A pin tumbler which must rotate to a specific position to allow plug rotation.
Source: Lock Industry Standards and Training (LIST) Council

Two Column Progression

(n.) A process wherein key bittings are obtained by using the cut possibilities in two columns of the key bitting array.
Source: Lock Industry Standards and Training (LIST) Council

Two Pin Master Key

(n.) A master key for all combinations obtained by progressing two bitting positions.
Source: Lock Industry Standards and Training (LIST) Council

Two Point Lock

(n.) A lock with two bolts which are thrown and withdrawn simultaneously, often in more than one direction.
Source: Lock Industry Standards and Training (LIST) Council

Two-Step Progression

(n.) A progression using a two increment difference between bittings of a given position.
Source: Lock Industry Standards and Training (LIST) Council

TXTL-60

(n.) A U.L. rating given to a container where the door has been tested against forcible entry with common hand tools and/or abrasive cutting wheels, power saws, and oxy-fuel gas cutting or welding torch and may further include nitroglycerin or other high explosives for a period of 60 man minutes. The total quantity of explosives employed may not exceed 8 ounces. Not more than 4 ounces is to be used in a single charge.
Source: Lock Industry Standards and Training (LIST) Council

Type 1

(n.) A UL rating given to an electronic combination lock able to withstand 20 man-hours of expert manipulation as well as other specifications as listed in UL 2058.
Source: Lock Industry Standards and Training (LIST) Council

Type 1F

(n.) A UL rating given to an electronic combination lock able to withstand 20 man-hours of expert manipulation as well as other specifications as listed in UL 2058. The lock also meets U.S. Federal Specifications FF-L-2740.
Source: Lock Industry Standards and Training (LIST) Council

Type 2

(n.) A UL rating given to an electronic combination lock able to withstand specifications as listed in UL 2058.
Source: Lock Industry Standards and Training (LIST) Council