The following Glossary of Locksmith Terminology is provided courtesy of the Master Locksmith Association (MLA). Click on a letter below to be taken to its corresponding terms.

Latch - The type of product with one bolt only, the bevelled springbolt or roller bolt, to latch or fasten the door, but not capable of being locked. Certain types, e.g. locking latches, nightlatches, or deadlatches, can, however, be locked by key or other means.

Latchbolt - See “Springbolt”.

Latchset - A latch complete with necessary furniture including a spindle, ready for fixing to the door.

Latchset furniture or latch furniture - A latchset, minus the latch.

Lever - A fiat shaped movable detainer in a lock, usually for the purpose of providing security and differs. The lever(s) in a lock have to be actually moved by the key to operate the lock. The belly of the lever is cut away to various depths to provide different combinations.

Lever mechanism - A lock mechanism having, as its principle feature, one or more levers.



Lever and warded mechanism - The lever mechanism with the addition of wards, usually for providing a greater number of differs. The addition of wards does not, however, increase the security of a lock. See “Wards”.

Lever handle - A piece of lock or latch furniture, usually on a rose or plate, for use as an alternative to a knob for operating the springbolt of a lock or latch. All British lever handles are spring-loaded to ensure the return to horizontal after use, but Continental lever handles are not usually spring-loaded and thus when used with British locks or latches, sometimes tend to sag below the horizontal after a comparatively short period of use, unless additional springing is included in the lock action.

Lever Pivot - The stump in a lock on which the levers swing.

Link Plate - The complementary member of box, desk and other locks which is fixed to the lid or some part of a cabinet, for example, and has one or more projecting links to enter the lock and engage the bolt.

Lip (of striking plate) - The projection on one side of a striking plate on the surface of which the springbolt of the lock or latch first strikes when the door is closed. It is usually radiused or bevelled to guide the springbolt.

Live bolt - See “Springbolt”.

Lock - A device operated usually, but not always, by a key, having one or more bolts or other members to fasten and secure a door, lid, drawer or other member.

Lockable bolt - A bolt that can be shot and locked in position by the use of a removable key.

Locking latch - A latch with a bevelled springbolt or roller bolt which is capable of being locked or secured, usually by key.

Lockset - A lock complete with necessary furniture including a spindle, ready for fixing to the door.

Lockset furniture or lock furniture - A lockset, minus the lock.

London strip - A steel bar fitted to the inside face of a door frame, shaped to accommodate the staple or striker of a rim latch lock.

Long shackle (LS) - A padlock shackle with a greater amount of clearance than the normal standard shackle.

Lubrication - On no account should oil be used to lubricate pin-tumbler cylinders. Graphite is the conventional lubricant for this mechanism.

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