How To Fix A Mortise Door Lockset

Mortise Lockset Parts

Multiple parts make up full mortise locksets. Nothing was standard during manufacturing 100 years ago, so each lock may be slightly different. Here are some general universal parts:

The lockbox is the carcass that contains all of the small parts within the lockset. It’s also the part that slides into the door. The latch is the part of the door that opens and closes with the twist of the door knob. It catches in the door frame and prevents the door from opening without the twist of a key or the knob. The lever is typically the doorknob assembly, but there are many parts within the lockbox that work together to make up this part. The deadbolt is the heavy-duty version of a latch that slides in and out of a door, and sits deeply into the door jamb. The cylinder is the keyed portion of the lockset. It locks and unlocks the door for passage, and connects to the other parts within the lockset to allow for operation.

Repairing a Full Mortise Lockset

Note: Whenever removing parts from the lockset or the door, place them in a small container. These parts can be easy to lose and expensive to replace.