What are Mortise Locks and Latches?
Mortise locks are locking latch mechanisms that require a rectangular hole in the door edge for installation.
Mortise latches have the same shape, but only a latch function. They don't lock. In old homes, some interior doors will have only mortise latches installed.
Tip: Mortise locks are durable, heavy, and, if you have old ones, worth keeping. Common problems such as weak latch tension are typically due to worn-out pins or springs. These can (and should) be replaced by an experienced locksmith who is familiar with mortise locks.