Knob lock

A knob lock is one worked by turning a knob instead of pressing down a lever handle. On many models the outside knob has the cylinder in its centre and the inside one a button or thumbturn to lock it.

It is used on internal doors, storeroom or utility doors, and on some houses built in the British or American style also on the front door. It is simple to fit and usually sits on a tubular lock.

It is not a good choice as the main lock of a home: the knob can be broken or forced round and the latch is usually short. If your front door only has a knob, add at least a key-operated bolt. We cover this under lock installation and security deadbolts.