Mortice Locks – Explained!March 11, 2014
What is a mortice Lock? – A lock which is set within the body of a door. These types of locks are typically found on wooden doors, the components of a mortice lock are recessed within the woodwork of a timber door frame; otherwise know as the pocket of the door. Mortice locks are supplied as sashlocks or deadlocks, sashlocks incorporating a handle and latch mechanism, which allows the lock to hold the door in a closed position.
Standard mortice lock use internal levers to lock and unlock the dead bolt. A key is inserted into the lock casing, which when turned will lift the levers inside the lock to the correct height, this allows the key to operate the bolt thrower which moves the locking dead bolt in or out. Lever locks can have different numbers of levers, depending on the application and security level required. Mortice locks can have 2, 3, 5 and 6 levers, the most popular are 5 Lever British Standard Lock, these conform to the latest British Standards and requirements for UK insurance companies.
Mortice locks can be purchased in two standard sizes, 64mm (2.5”) and 76mm (3”), other sizes are available these includes 50mm and 102mm. Doors with a large pane of glass and aluminium doors have a very narrow stile, the section that a mortice lock is fitted too, and therefore need a narrow mortice lock case, such as the 50mm lock.
The case depth and backset measurements on mortice locks are generally the most important. The case depth (A, see below) is the measurement from the front face plate to the very back or the lock and the backset measurement (B) is again from the front face plate to the centre of the key hole.
Other types of mortice lock are available for different door types and applications.
Horizontal Mortice Lock
Mortice lock case with dead bolt and latch, however the key hole and spindle for knob turns are horizontal to each other, rather than the more standard vertical to each other. Horizontal locks are most commonly found on older style period doors, these often have ornate large door frames that would hamper the operation of a handle of knob of a standard mortice lock.
Sliding Door Locks
Making some what of a come back are sliding doors, which offer great space saving within small rooms. A normal dead bolt can not be used with a sliding door, so instead a hook or claw bolt is used instead. Operated in the same way as deadlock and sashlocks.