LOCKS - Leading Construction and Building Group

Dial A Contractor
Go to content


A number of lock cases have varied dimensions in respect of the backset and centres e.g. a standard upright mortice lock has a backset of 57mm and a narrow stile upright mortice lock has a backset of 43mm. The actual widths of the casing and striker plate also differ with certain lock cases.

Dead lock
A lock which is worked from both sides by a key only and typically fitted within the door leaf thickness (mortice type). It usually has no door knobs and so may need a door pull.

Mortice lock
A lock set in a mortice (within the door leaf thickness) the lock is hidden and the joinery needs more skill to fi t than that of a rim lock.

Rim lock
A lockable “Rim latch” usually opened by a key from the outside and by a knob from the inside; which was commonly referred to as a “Yale lock” in the 70’s and 80’s (Yale was then the actual manufacturer of this type of lock).

Rim latch
A door latch which is fixed to the surface of a door leaf (surface mounted) on the edge of the shutting stile, with a matching casing on the door jamb to encase the latch.

A lock with a cylinder which can be turned once the right key is inserted in a slot, raising pin tumblers or disc tumblers to the right height. The cam in the centre then turns and releases the bolt of the locking case (opening the lock).

Lever lock
Could be described as the traditional mortice lock to which many refer to as a 2 lever or 3 lever lock. The key must move several levers to release the bolt when it is shot or withdrawn e.g. a 3 lever lock will have 3 levers to move.

The term Lockset indicates a combination of a lock (and cylinder where appropriate) and a pair of lever handles.

Rebate Set Kits
Locks fitted to double leaf doors with rebated meeting stiles require Rebate Conversion Sets/Kits. The Figure to the right illustrates the two component parts of a typical Rebate Conversion Set, namely the striking plate portion which is fitted to the inactive leaf and the forend strip which is fi tted behind the forend plate of the lock in the active leaf.

Rebate Conversion Sets/Kits typically suit doors with 13mm deep rebated meeting stiles.

Available in the following finishes;
• Satin Chrome (SC)
• Brass (PL)

Note: Rebate conversion Sets/Kits are not available for many European style lock cases; therefore doors without rebates should be specified if these types of lock cases are to be used.


Electric locks
Operate typically where the striking plate or latch has a release catch which can be operated remotely or via a wired button; also operated by key inside and out. Electric locks need to be hand specifi ed i.e. left or right, open in or out. Most require a 12V or 24V connection via a transformer. These types of locks are seldom used in residential applications and seen more in offi ce and commercial type applications.

Padlocks are used to lock other locking devices e.g. pad bolts, especially on security gates, tool shed doors, etc. Padlocks are available in a number of different sizes and manufactured to suit specific applications e.g. a pad lock used in a high security application has a more robust casing and manufactured from high tensile steels with a higher pinning of the actual locking cylinder.

Pinning of padlock cylinders are usually as follows;
• 4, 5, 6, 10 and 12 pin

Widths of locks also differ as follows;
• 30mm, 40mm, 50mm, 60mm, 70mm with some locks going up to 90mm

The shackle heights of padlocks differ substantially depending on the width; standard padlocks have the following typical shackle heights which increase with the width of the lock i.e. the bigger the lock the higher the shackle.
• 17mm, 23mm, 27mm, 37mm, and 40mm with extra long shackle varying from 80 to 200mm

Panic locks
These are locks in which the handle or panic device (panic bar) withdraws the latch and deadbolt simultaneously in a panic situation. These are typically only found in public places or fi re escapes and can also be classed as emergency locks.

Emergency locks
These are typically used only on exit routes in public places and to doors which usually have no access and are only there in the case of emergency. They are typically inoperable from the outside as many emergency exists are directed to the exterior of building or access corridors/passages. (See Panic locks above).

Security locks
Security locks can be described as locks that are used to prevent illegal entry particularly for external doors and have lock cases manufactured from thicker material with hardened steel or composite latches and double throw deadbolts.

Cupboard locks
Are a lot smaller than a typical mortice or rim lock and are fi tted on the inner face of the cupboard door. They act more as a means of locking the cupboard to prevent unwanted access rather than for security reasons.

They are available as 1,2 and 3 lever type locks; with lock case sizes of 51mm, 64mm and 76mm and as cylinder type locks with different cylinder lengths. Also available are cam locks which can be used for cupboard doors but are typically used for drawers.


ADDRESS: PO BOX 16123, PANORAMA, 7506    
CAPE: 021 300 1098   BLOEMFONTEIN: 051 004 0119   DURBAN: 031 100 1164   JOHANNESBURG: 011 568 0712   PORT ELIZABETH: 041 004 0007   PRETORIA: 012 004 0239    POLOKWANE: 015 004 0199
FACSIMILE: 086 650 5033    EMERGENCY CONTACT: 082 509 3022  

Back to content