Mortise, cylindrical or rim lock — which door lock

Three ways a lock body attaches to a door, each with a different prep and a different security level.

Mortise lock

The lock body is buried in a pocket cut into the door edge. Strong, neat, and the standard for main and internal doors in India. A mortise sashlock has a latch and a deadbolt; a mortise deadlock has only the bolt; a mortise latch only the latch. Security depends on the bolt throw and the cylinder — specify a hardened bolt and a drill-resistant euro or pin cylinder for external doors.

Key dimension: the backset (door edge to spindle centre, commonly 60 mm or 65 mm) and the case size. Match both to the existing mortise if you are replacing.

Cylindrical (tubular) lock

A round latch bore through the face and a smaller cross-bore for the spindle. Fast to fit, common on internal and commercial doors, and easy to standardise across a building. Less resistant to a determined attack than a good mortise lock, so pair it with a separate deadbolt on external doors.

Rim lock

Bolts onto the inside face of the door — no cutting into the leaf. Used as a secondary night latch, on thin doors, and where you cannot mortise (some glass-and-frame doors). The night latch (rim automatic deadlatch) is the classic Indian flat front-door second lock.

Matching an existing door

Send a photo of the door edge with the current lock out, plus the backset and case height. Most mortise bodies can be matched or a template supplied so the new keeps line up.

We stock mortise sashlocks and deadlocks, cylindrical locksets, night latches and the cylinders to suit — keyed alike on request for a building.