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.

Safe Lock - A general term for the many varieties of key operated and other locks for safes.

Sash lock - An upright mortice lock, consisting of a latch bolt and a key operated bolt.

Sash ward - Used in rim and mortice locks, alone or in conjunction with levers for the purpose of obtaining or increasing the differs. Formed pieces of concentric metal are affixed around the inside of the keyhole. It also serves as a keyhole bush. The bitted key passes over these wards to operate the bolt. Little security is given when sash wards are used by themselves. See “Skeleton Keys”.

Scotch spring lock - A two-bolt rim lock with the reversible springbolt above or below the horizontal plane of the follower. The scotch spring tapers and its thicker end is fastened to the lock case, the thinner end bears on a pivoted arm fixed to the end of the bolt. There is usually a cut-out in the cover to reveal the end of the spring.

Servant key - The change key of one (or more than one if of the same change) lock in a master keyed or grand master keyed suite.

Set Screw - One which tightens or fastens another part after assembly or adjustment.

Shackle - The hinged, sliding or swivelling loop shaped member of a padlock. The heel of the shackle remains always in the padlock body and the toe of the shackle comes out when unlocked. A double locking padlock gives the greatest security against forcing because there are two separate bolts locking outwards in opposite directions, one into a niche in the heel of the shackle, and the other into the toe of the shackle. This is sometimes called heel and toe locking.

Shank (of key) - The part of a pin or pipe key between the bow and the end, excluding the blade.

Shear Line - The term is used to denote the line of the circumference of the plug in the bore of a pin tumbler cylinder.

Shoot - 1. The outward movement of a lock bolt and the distance which it travels under the action of a spring or key. Shoot applies more particularly to spring bolts, throw being a better word for dead bolts.
2. The sliding part of a door bolt.

Shoot (of bolt) - The distance a springbolt moves under the action of its spring.

Shoulder (or bow stop) - The projection or ear or shape that controls the point at which a cylinder or disk tumbler comes to rest when fully inserted into the lock. It is the datum point from which spacing cuts are measured.

Side Bar - This is in addition to the existing pin or disc mechanism, and is a bar usually along the length mechanism and does not allow rotation until the mechanism is correctly lifted and can be directly controlled by the key.



Side Wards - Notches cut into the sides of bitted keys so fashioned to enable the key to turn.

Skeleton key - A key, the blade of which has been cut away sufficiently to allow the blade to pass any wards or obstructions within the lock and throw or retract the bolt. There is no universal skeleton key. One has to be prepared for each series of warded locks. Skeleton keys cannot be made for lever and cylinder lock mechanisms.

Sliding grilles - Steel sliding grille gates in single or double leaf, running on top and bottom guide tracks, locked by padlock or integral lock.

Sliding Lever - A lever which slides between or on guides instead of swinging on a pivot.



Spindle - That part of the door furniture usually of square section which passes through the follower hole and is fitted to the knob(s) or lever handle(s) to operate the springbolt.

Spoon - The flattened end of a padlock shackle containing the bolt hole or slot which the bolt enters.

Spacer - A distance piece of thin metal placed between the levers of some locks.

Spacing - The term used to describe the horizontal distances across a key blade or bit.

Spiral - Spring 1. A spring made of wire to approximately V shape like a feather spring; with one or more coils formed at the apex of the V to fit over a stump in the lock case. 2. A coil spring



Spring-loaded - Moved under the control of, or against the pull of, a spring fixed at one end.

Spring shackle padlock - A padlock, the shackle of which springs open when unlocked, and is locked by snapping to.

Springbolt - Sometimes called the latchbolt. A bolt having the outer edge shaped by bevelling of the vertical face. It is a bolt which may be pushed back into the lock-case and will return to the extended position without mechanical assistance.

Springlatch - A latch with one bevelled springbolt that locks the door when shut. It is opened by key from the outside and by knob from inside.

Staple - 1 A box-like fitting on the jamb of an inward opening door, and into which the bolt or bolts of a rim latch or lock shoot when door is closed. (It is sometimes referred to in Scotland and the North of England as a Bosshead). Some staples are lipped to act as a guide for the springbolt.
2. Part of a hasp and staple for use with a padlock. The padlock shackle passes through the eye or hole in the staple.

Steel lining - Steel sheet linings applied to external or both faces of a door; usually screwed and bolted through.

Stile - A vertical member of a door.

Stop knob (snib) - A device incorporated in some latches and locking latches to hold the bolt retracted or deadlock the bolt when door is closed.

Stop button(s -) There are generally two in number. They are incorporated in the forend of certain cylinder mortice nightlatches or locks. One button, when depressed, renders the outside furniture inoperable and the other, when depressed, restores the power of operation. They are useful for privacy and on vestibule doors. They are sometimes referred to as “stopworks”.

Straight cabinet lock - A cabinet lock, with no flange on the case, for flush fitting to cupboards and drawers.

Striking plate - Sometimes referred to as a “striker”. It is a shaped flat metal plate fixed to the door frame or jamb with one or more bolt holes into which the bolt or bolts shoot. There is a shaped projecting lip on one side to guide the springbolt. It is used with all mortice locks or latches, and with rim locks or latches with reversed springbolt on an outward opening door.

Sub Grand Master Key - A key which will operate all locks in its own main group or (sub-grand suite) of a grand master keyed system.

Sub Master Key - A key which will operate all locks in its own smaller group (or sub-suite) of a grand master keyed system.

Suite (of locks) - A group or collection of locks and/or locking latches and padlocks of different types and changes incorporated together under a master key or grand master key.

Tel. 0800 0 187 187

e-mail: callcentre@timpsonlocksmiths.co.uk