Parts of a Door Lock Set

A door lock set might be included with the doorknob, or it can be a separate deadbolt. A deadbolt can have a latch knob that turns to lock and unlock the door from the inside. Some deadbolts do not have a latch knob and require a key from the inside, as well as the outside of the door.

Latch

If the lock is part of the door knob, the door knob will typically include a small knob in its center. This can be turned from side to side, or pushed up or down to lock and unlock the door. If it is a deadbolt, it may have a latch on the inside that turns to lock or unlock the door, called a latch knob.

Case

The latch case is the casing around the latch knob of the deadbolt. It can also be the casing around the key slot.

Cylinder

The cylinder is where the key is inserted. It is cylindrical and recessed in the door.

Tang

The tang is a metal bar that runs from the cylinder, through the door, to the latch case. The tang runs through the back plate which is located between the latch case and the door.

Screws

On the inside of the door the latch case is screwed to the door, holding the entire lock in place with the latch case crews.