L-handle
n. an L-shaped handle assembly which may be lockable

L-handle lock
n. a cabinet lock with an L-shaped handle

labeled door
n. a door which has a fire protection certification by one of the recognized underwriting agencies

labeled exit
n. a labeled door equipped with labeled hardware that can be used for building egress

laminated padlock
n. a padlock whose case is constructed of separate plates usually riveted together

LAN-alarm web camera
n. a self-standing surveillance camera having alarm compatible for IR devices, switches and onboard website, Internet email sending capability

large format interchangeable core
n. an interchangeable core which is too large to fit into a small format interchangeable core housing

laser cut
adj. 1. a way of cutting a key so that the roots of adjacent cuts are connected by a straight-line cut; 2. a way of cutting a key so that the root of a shallow cut is widened until it intersects the included angle of an adjacent deeper cut

latch
1. n. a mechanical or magnetic door fastener which can automatically keep a door, gate, etc., closed, 2. v. engagement of a latch when a door, gate, etc. is pushed or pulled closed

latch bolt
n. a spring actuated bolt, normally with one or more beveled surfaces, which, when aligned with the strike, engages it automatically

latch guard
n. a plate or combination of interlocking pieces designed to block access to the edge of a latch when the door is shut

latch tube
n. the encasement portion of some types of lockset that contains the latch and may also contain its operating mechanism

latching speed (of a door closer)
n. the final speed of a door just prior to closing

latchset
n. a non-locking device which contains only a latch bolt, a means of operating said latch and all required trim

layout tray
n. a compartmented container used to organize cylinder parts during keying or servicing

lazy cam/tailpiece
n. a cam or tailpiece designed to remain stationary while the cylinder plug is partially rotated and/or vice-versa

leading face
n. the door face closest to the strike side of the jamb when the door is open

leaf
n. 1.One half or section of a hinge 2. One door in a set of double doors 3. One section of a multiple section door

left hand (man door)
adj. pertaining to an inward swinging door with hinges on the left side, using the outside of the door as reference

left hand reverse bevel (door)
adj. pertaining to a left handed door which swings outward

leg irons
n. -pl. a pair of ringlike fetters, connected by a short chain or straight member, designed to be locked about the ankle

levels of keying
n. pl. the divisions of a master key system into hierarchies of access

lever (combination lock)
n. part of a combination lock that engages the drive cam, when the proper combination is supplied, and is directly attached to the locking bolt

lever handle
n. a turn device in the general shape of an "L" used on certain locks and latches, as an alternate to a knob for ease of use

lever nose
n. the hooked portion of a lever that engages the drive cam in a combination lock

lever pack
n. a set of lever tumblers

lever rig
n. any device which utilizes a fulcrum with a long bar or pole as a means to apply pressure while drilling

lever tumbler
n. a flat, spring-loaded tumbler which usually pivots on a post. It contains a gate which must be aligned with a fence to allow movement of the bolt.

LFIC
abb. Large Format Interchangeable Core

LH
abb. left hand

LHR
abb. left hand reverse bevel

LHVD
abb. left hand vertical down

LHVU
abb. left hand vertical up

lift arc
n. the distance a lever tumbler may be raised by a key from its at-rest position

linkage
n. 1. any of various parts in a lock that help transfer motion to the bolt of a lock from a cylinder, turnpiece or other actuator not mounted to or touching the bolt/lock case, 2. part of the interconnected boltworks of an automotive lock

lip (of a strike)
n. the extended (usually curved) leading edge of a strike

lite
n. a hole in a door or wall to admit light, usually with glass or another transparent or translucent pane

loading tool
n. a tool which aids installation of cylinder components into the cylinder shell

LOBC
abb. 1. locked on by combination, 2. (sic) locked on back cover

LOBC index
n. the index to which a combination is dialed in order to remove the lock's cover

local alarm
n. an alarm that is annunciated in the immediate vicinity of the activating device

lock
n. any device which prevents access or use by requiring special knowledge or equipment

lock bumping
n. a picking technique that utilizes a configured key forcefully impacted into the keyway

lock-in
adj. of or pertaining to a combination lock that is inoperable because the last number of a combination is set in the forbidden zone

lock service package
n. a kit offered by the manufacturer or distributor of a product, which contains what he deems required to properly service the product

lock stile
n. the vertical edge of a door designed for lock or latch installation

lock window
n. an opening in the case of a lever tumbler lock for viewing the fence entering the gates of the levers

lockdown bar
n. an assembly which permits a laptop computer to be used, opened, closed, but not removed from a premises, often secured by a padlock

locked closed
adj. of or pertaining to a condition wherein the bolt(s) are engaged and the lock(s) are restricting access

locked on by combination
n. a combination lock cover that can only be removed in conjunction with dialing the combination or while the lock bolt is in motion

locked open
adj. of or pertaining to a condition wherein the bolt(s) are engaged and lock(s) are not restricting access

locker lock
n. 1. any of various types of locks designed for a specific mounting preparation commonly used on lockers as well as other applications, 2. any of various locks used to lock lockers

locking lug
n. a fixed component of a safe which locks the safe door in place in the locked position. See appendix

locking lug nut
n. a lug nut which requires the use of a key or special wrench

lockout
n. any situation in which the normal operation of a lock or cylinder is prevented

lockout key
n. a key made in two pieces. One piece is trapped in the keyway by the tumblers when inserted and blocks entry of any regular key. The second piece is used to remove the first piece.

lockset
n. a locking device, complete with trim, mounting hardware and strike

locksmith
n. a person with the knowledge and ability to select, install, service and bypass all the components of an electrical or mechanical lock

LoCo
abb. low coercivity

lost ball keying
n. a construction keying method that uses a tiny ball(s) in the pin stack to allow construction master key operation. The ball(s) may be removed from the pin stack without disassembly of the cylinder.

low coercivity
adj. a low energy form of magnetic encoding measuring 300 Oe which is not very resistant to accidental erasure

lug door
n. a usually rotatable safe door which has projections that interlock with the safe body to retain the door