Tubular lock

A tubular lock is one with a cylindrical body fitted into a round hole drilled in the face of the door, with the latch housed in a tube that runs through the edge. It is very common on internal doors and with knobs, because it goes in with two drilled holes and no case has to be cut out.

The name is also given to locks with a tubular key, the round, hollow key with the cuts on its rim, which you see on vending machines, cabinets and some padlocks.

Tubular locks on internal doors are low security: they are fine for a bathroom or a bedroom, not for a front door. If you have one on an outside door, it is worth replacing it with a lock designed for the job. More under lock installation.