Components & reference points
The lock bolt
The bolt is the moving part that engages with a strike plate to hold or lock a door. Its shape and operation depend on the function of the lock.
THE KEY POINT TO REMEMBER
A deadbolt moves well: it extends to lock and retracts to unlock. 'Deadbolt' does not mean immobile.
Latch bolt and deadbolt: two functions
The half-bolt, usually beveled and spring-retained, holds the door in place after closure. The handle typically allows retraction of the bolt.
The deadbolt is operated by the locking mechanism, often via a key or a button. Unlike a standard half-bolt, it does not simply enter the strike plate under pressure during closure.
Other types of bolts
Bolts can be rectangular, round, oval, or hook-shaped. A hook design may be suitable for a sliding closure, where the retention principle differs from that of a hinged door.
Some mechanisms use pivoting components or special movements. The shape alone does not establish a security classification: the complete mechanism and its strike plate must be assessed.
The decisive role of the strike plate
The bolt must penetrate sufficiently into its receiving chamber without abnormal friction. A sagging door or a misaligned strike plate may prevent proper closure, even if the lock case remains functional.
Every locking point on a multipoint lock must engage correctly. If the handle is difficult to lift or the key is stiff, have the mechanism checked before repeated force damages the parts.
Can the bolt alone be replaced?
It depends on the lock's design and the availability of parts. Some mechanisms can be repaired; others require replacement of the lock case or the entire unit.
The diagnosis must also check the handle, cylinder, fittings, and frame. When a replacement is selected, the dimensions, operating direction, and strike plate compatibility guide the choice.
IN IMAGES
MULTISECU ADVICE
Uncertain about your lock?
A photo of the mechanism, along with some details about your door: we help you identify the right solution.