Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Access control
Enabling the optimum management of personnel movement within a building or locations.

Alike change
More than one lock or latch which can be operated by the same key.

All to pass
Often referred to as “locks to pass”, i.e. a number of locks which can be “passed” or opened by the same key.

Armoured cylinder
A high security cylinder is protected or ‘armoured’ against drill attack using hardened pins and plates.

Automatic deadlocking
A small auxiliary bolt next to the main bolt hits the striking plate or staple and is pushed in every time the door is closed. This action automatically holds the main bolt in the locked position.

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Auxiliary bolt
An additional bolt which is activated by the strike when the door is closed, automatically deadlocking the latchbolt against end pressure.

Backplate
The plate, fixed on a door, to which the moving parts of a lock or latch are attached.

Backcheck
The feature of a door closer unit that prevents shock and possible damage when the door is forcibly opened.

Backset
The horizontal distance from the edge of the door to the central line of the cylinder key hole.

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Bathroom lock
A lock with latchbolt operable on both sides by furniture and deadbolt operated from inside only; usually by thumbturn.

Bit (of key) or key bit
That part of a key which is specially shaped or notched to operate the mechanism of its own particular lock or latch.

Bitting
The shaping or notching of a key blank to transform it into a key to operate its own lock or latch.

Blade (of key)
That part of a cylinder or lever key which is to be or has been notched.

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Blank (key) or key blank
A partly made key, which has been shaped to enter the keyhole of a certain type of lock or latch, but of which the blade has not been finally notched to operate any individual lock.

Bolt
The part of a lock or latch which provides the fastening or engagement by protruding from the case or forend to engage in the staple or striking plate.

Bow (of key)
That part of the key which is held in the fingers when operating the lock or latch.

Box strike
A strike in which the bolt recess is enclosed or boxed, thus covering the opening in the jamb.

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British Standard 3621
This is the level of security strongly recommended by the Police and Insurance Companies. The standard includes many security features, ensuring that the lock is resistant to attack by drill, saw or force.

BS5725
Specification for panic bolts and panic latches, mechanically operated by a horizontal push bar. Its function is to specify criteria within given limits whilst also recommending good practices.

BS5750
ISO9001 International quality system.

BS5872
Specification for locks and latches for doors and buildings which provide physical dimensions, as well as performance and test data.

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BS8220
The security of buildings against crime: Part 1 which provides technical guidance of the security and burglaries. BS8220 is normally the first consultation point when specifying.

Cabinet lock
A generic term to include all locks of any type for use on pieces of furniture, such as cupboards, drawers, chests, boxes and the like.

Cam
Usually a tongue fixed to the end of the plug of a cylinder lock or latch.

Case
That part of a lock or latch containing the mechanism.

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Casement window
A window with a sash hung about a vertical axis by hinges at the side.

CEN standards
Pan European standards which will grade products by security level.

Centre hookbolt
On Chubb multipoint locks - used to grip the door sash and frame together faciltate compression.

Change key
The key which opens one particular lock. Usually a term used with Master-Keyed Suites.

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Claw bolt
A type of deadbolt having claws which swing out side ways when the bolt is shot. Such locks are usually fixed to sliding doors.

Change (of key)
See Differ

Close shackle padlock
A padlock the body of which is built up so that the minimum amount of shackle is visible when locked. Improved security against forcing or use of bolt-croppers.

Concealed fixing
Once fitted the fixings of the lock or security device are hidden from view.

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Connecting bar
The thin metal strip fitted to the rear of the cylinder plug which operates the spring bolt in a cylinder rim lock. It passes through the thickness of the door, and is usually indented at intervals to ease shortening to the correct length.

Connecting screws
The two screws which fix the cylinder body to the mounting plate.

Construction keying
Systems used to allow contractors to gain entry to a building during construction but to prevent entry by the same contractors after the building has been occupied or handed over.

Cylinder
The mechanism that operates the lock.

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Cylinder key
A key, having a bow and long blade in which Vee cuts are made along the upper edge to operate the pins and drivers in a pin tumbler mechanism.

Cylinder mortice lock
A mortice style lock operated by either a euro or oval cylinder. Most commonly used in master key systems. Available as either a deadlock or sashlock (doorlock).

Clutch head screws
See one-way screws.

Cylinder rim lock
A surface fitting lock. Dependant upon application products range from High Security BS3621 locks through to traditional nightlatches. The unique feature about most cylinder rim locks is that once the door is closed it is always locked.

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Cylinder rose
A shaped metal disc which surrounds the outer face of the cylinder of a cylinder mechanism assembly. Usually stands slightly proud of the outside face of the door.

Deadbolt
A bolt which is not activated by a spring. When locked the bolt cannot be returned by end pressure.

Deadlatch
A nightlatch or latch, the springbolt of which can be locked (or deadlocked) by key or other means.

Deadlock
A single bolt mortice lock which can be used to supplement a standard cylinder rim lock on the front door.

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Deadlocking
On cylinder rim locks with this function, once you have left the house and closed the door, insert the key in the cylinder and give it an anti-clockwise turn. This deadlocks the bolt preventing it from being pushed back.

Delayed action
A feature of a door closer which holds the door in the open position for a number of seconds before the closing action commences. This feature is ideal for use by the handicapped, the aged and people with prams, trolleys etc.

Differs
An abbreviation of “different combinations” (see key combinations).

Disc tumblers
The small shaped discs (usually of metal) in the disc tumbler mechanism which are the means of providing different combinations.

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Disc tumbler locks
A cylinder lock having discs instead of pin tumblers.

Double locking
The manual means by which the latchbolt on a cylinder rim lock is deadlocked. Insert the key in the outside cylinder and give it a reverse turn. The inside handle is now locked and unopenable until the key is reinserted into the outside cylinder. Prevents unautorised entry by someone breaking adjacent glass, reaching in and turning the handle.

Double throw latchbolt
On Chubb multipoint locks - an extra key turn projects the latch a further 6mm and secures it.

Drill resistant
Locks and cylinders can be protected against drill attack by utilising hardened steel plates and pins.

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Drivers
Usually the upper of each pair of pin tumblers in the cylinder mechanism. The lower are known as pins.

Dummy trim
A non-operating door trim which is installed for appearance or as a door pull only.

Easy action
A lock is designed so that only light spring pressure is required to move the bolt.

Electric strike
An electrical device that replaced a regular lock strike to enable a door to be released by remote control.

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Emergency key
A key supplied with Hotel locks. These locks have a feature which, when applied, prevents entry by normal service keys, master keys or grand master keys. At all times entry can be gained by the emergency key which suit those group of locks.

Escutcheon
The cover for the keyhole of a mortice or similar lock. (Also known as rose).

Euro cylinder
The security device which operates a euro profile cylinder mortice lock. Supplied as either single, double or single with thumbturn operation.

Face plate
A strip of metal fixed to the outer edge of a mortice lock which fits flush with the door edge.

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Final exit door
The exit door through which entry must later be obtained, and so cannot be bolted. Usually the front entrance door. N.B. - As one must rely on the lock only for security, it is very important that a high security lock should always be fitted to a final exit door.

Follower
That part of the lock mechanism containing a square hole to admit the spindle (to which door handles are attached) which pulls back the springbolt when turned.

Force resistant
Cylinder rim locks which have an automatic deadlocking feature are protected against jemmy attack because the bolt is held in the locked position every time the door is closed. High security cylinder rim locks also have an extended striking plate giving a stronger fixing to the frame and so are resistant to an attempt to kick the door open. High security mortice locks have a box striking plate too.

Forend
That part of the lock or latch through which the bolt(s) protrude, and by which the lock or latch is fixed to the door.

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Furniture (door handles)
The additional items needed, which are screwed to one or both sides of the door to enable a lock or latch to be manually operated.

Grand master key
A key within a system that operates all locks in a number of separate groups which have their own master keys.

Handing
For some locks (usually specialised locks for use in the commercial sector) the handing of the door to which the lock is fitted must be specified when ordering.

Hasp & staple
A fastening in two pieces to be secured by a padlock. (Also known as a padbar).

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Hold open
The feature of a door closer unit which enables a door to be held in the opened position until released.

Holdback
A snib, button or other device which can hold the bolt in the retracted position.
Hook bolt
A lock with a hook shaped bolt. Such locks or latches are usually fixed on UPVC or sliding doors.

Horizontal lock
A mortice or rim lock having the follower hole further from the forend than the keyhole, and in the same horizontal plane.

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Jamb
The vertical part of a door or window frame. In some areas the top rail of a door frame is referred to as the top jamb.

Keep
A term sometimes used for a staple or striking plate.

Key
A small removable device for operating the mechanism of its own lock.

Key blank
A partly made key, which has been shaped to enter the keyhole of a certain type of lock or latch, but of which the blade has not been fully shaped to operate the mechanism of the lock.

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Key change
A term sometimes used instead of “differ”. The change or differ of the key is generally indicated by numbers and sometimes numbers and letters marked on the bow.

Key combination
This is the number of possible key combinations before the same key is repeated.

Possible different key combination:-
2 lever = 12
3 lever = 150
5 lever = 500
BS3621 5 lever = 1,000
5-pin cylinder= 20,000
6-pin cylinder = 100,000
HSC = 20 million

Keyhole
The hole into which the key enters to operate the lock or latch. Often referred as the keyway, particularly in a cylinder mechanism.

Keypad
Used in conjunction with an electric strike to provide an easy means of Access Control. Most common keypads require a four digit combination to be entered.

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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.

Latchbolt
A bolt having a bevelled edge. (Also see springbolt).

Levers
The traditional method by which a mortice lock is operated; 5, 3 or 2 lever mechanisms. The cutting on the key raises the levers until they form a horizontal plane. The deadbolt can then be thrown into the locked position.

Lever handle
Door furniture for use as an alternative to a knob for operating the latch of a lock. Lever handles can be springloaded or non-springloaded. Springloading ensures the handle returns to the horizontal position after use. Non-springloaded handles rely on the springing in the lock.

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Lever lever
Door handle used in conjunction with Chubb multipoint locks.

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

Lever pad
Door handle used in conjunction with Chubb multipoint locks.

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. Usually radiused or bevelled to guide the springbolt.

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

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

Long shackle padlock
A padlock shackle with a greater amount of clearance than the standard shackle.

Lubrication
Applied to the cylinder mechanism to ensure smooth operation. Chubb recommend regular use of WD40 on moving parts, otherwise a graphite powder for the cylinder plug.

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Master key
A key which will open a series of locks in a Master Keyed Suite.

Master keyed
A lock or latch capable of being operated also by a Master Key as well as its own change or servant key.

Mechanism (of locks or latches)
The arrangement of the component parts and the manner in which they perform to achieve the required security and differing when operated by its key.

Mortice
A hole cut into the thickness of one edge of a door to receive a mortice lock or latch.

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Mortice lock
A lock designed to be recessed into the edge of a door, rather than being mounted to its surface.

Mortice nightlatch
A hybrid between a mortice lock and a cylinder rim lock/nightlatch. The automatic deadlocking function by means of a small auxiliary bolt ensures that every time the door is closed it is locked. Ideal for flat entrance doors.

Multipoint lock
High security locking mechanism for doors that offers a range of 'locking points' often incorporating hooks, rollers, mushrooms and deadbolts.

Mushroom driver
A driver in the cylinder mechanism which has a mushroom shaped head. These provide a very effective anti-pick element against being lifted by a lock-pick or similar.

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Narrow case lock or latch
A rim lock or latch the case of which is made specially narrow, usually less than 75mm wide, for fixing to the narrow stile of a panelled or flush door.

Nightlatch
A rim or mortice latch with a bevelled springbolt or roller bolt which shoots when the door is closed, but can be withdrawn by key from outside and by knob or lever handle from inside. Usually provided with a stop knob, slide or snib to hold the bolt retracted and to deadlock the bolt when shot in the closed position, even against the action of the key.

One-way screws (or clutch head screws)
Screws with specially shaped heads to prevent removal by conventional screwdrivers.

Oval Cylinders
The security device which operates an oval profile cylinder mortice lock. Supplied as either single,double or single with thumbturn operation.

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Passage set
A latchset with knobs or levers on both sides of a door but no locking function.

Passing (or to pass)
Any key which operates a lock is said to pass the lock. If locks are made “alike change” one key will pass all the locks.

Pin tumbler mechanism
The mechanism incorporated in a Cylinder Rim Lock or Padlock. The cylinder houses the pins and drivers under spring pressure. The correct key lines up the plug and cylinder, thus allowing the plug to rotate and the lock to be operated.

Pins
Usually the lower of each pair of tumblers in the cylinder mechanism. The upper are known as drivers.

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Plug
The part of the pin-tumbler cylinder mechanism into which the key enters and which the key turns. It houses the pins of a pin tumbler cylinder mechanism.

Privacy set
A lock used on bathroom and bedroom doors having an inside button or turn knob to lock the knob or lever with an emergency function which will unlock the set from the outside.

Prokey
High security patented cylinder system. Operates on 7 pins and has achieved CEN 5.

Rebate
The stepped shaped reduction or recess cut along the meeting edges of each of a pair of swing doors leaving projections which overlap when the two doors stop on each other at closing.

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Rebated (lock or latch)
A mortice lock or latch with a forend specially shaped to correspond with the shaped meeting edge of the door for which it is intended.

Rebate Set
Used on overlapping double doors or single doors closing into the frame. The rebate raises the height of the edge of the door to allow the mortice lock to be fitted flush.

Rectangular padlock
Otherwise referred to as a block lock. Usually used on roller shutters or double gates.

Repeat differs
The supply of differs which have been issued previously. Usually associated with Master Keyed suites and where a replacement lock is required to have the same differ as the original.

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Reversible latchbolt
On mortice door locks (sashlocks) the latchbolt has a bevelled edge. This edge hits the striking plate and closes the door. Depending on whether the door is hinged on the right or left determines which way the bevelled edge of the bolt needs to face. On all Chubb mortice locks the latchbolt can be reversed.

Rim cylinder
A cylinder which connects to a rim lock through the door, allowing external operation.

Rim lock, Rim latch
A lock or latch which is mounted to the surface of a door, rather than inserted into the edge of a door.

Roller bolt
A springbolt made in the form of a roller, instead of being bevelled.

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Roller lock
On Chubb multipoint locks, stainless steel rollers are available providing a tight weather seal for doors.

Rose (or ring)
A shaped metal disc which surrounds the outer face of the cylinder.

Rounded forend
Used when the mortice for a forend is cut out using automated machinery.

Sashlock
A 2 bolt mortice lock used in conjunction with door handles which operate the latchbolt. Commonly referred to as a door lock.

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Sash Window
A 2 piece window comprising of top and bottom sections which move independently of each other.

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.

Shackle
The looped metal locking section of the padlock.

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

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Shootbolts
On Yale multipoint locks - a sintered steel bolt optional extra to secure the head and sill of the door into the frame.

Snib
The snib is the mechanism by which the bolt can be held back, (put ‘on the latch’). It can either be a button with slide movement, or a push movement.

Spindle
The part of the door handle usually of square section which passes through the top hole follower in a mortice door lock to operate the springbolt.

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

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

Stainless steel faceplate
On Yale multipoint locks - the exterior plate to fix the lock in situ within the door.

Staple
1. A box-like fitting on the jam of an inward opening door, and into which the bolt or bolts of a rim latch or lock shoot when door is closed.
2. Part of the hasp and staple for use with a padlock. The padlock shackle passes through the eye or hole in the staple.

Stile
Also referred to as door frame. Commonly there is a standard stile or narrow stile.

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Strike
A device fixed in or on a door jamb into which the lock or latch bolt engages when the door is closed.

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.

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Survey Form
A chart on which master key details, door lock and key information is kept.

Throw
The distance a deadbolt extends from the case under the actions of its key.

Thumbturn
A small fitting on the cylinder found on the inside of a door which is gripped between thumb and finger to operate the deadbolt. Should not be used on glass or wood-panelled doors. Ideal for fire exit doors where escape is always needed.

Trim
Commonly referred to as door furniture.

Tubular mortice lock
One having a tubular shaped case and requiring bored (round) holes rather than a chiselled rectangular mortice.

Tumbler
A component of a lock or cylinder which prevents operation of the lock mechanism except by insertion of the correct key.



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