How Does A Mortise Lock Work

- Apr 30, 2019-

A mortise lock needs a mortise, or a pocket, in the door frame to operate correctly. The bolt of the lock fits into the mortise. Because it uses the strength of the door frame, a mortise lock is far more secure than other locks that attach to the outside of a door frame.

There are four parts to a mortise lock other than the mortise itself. The main one is the lock body. This is the part that is fitted within the door. You won’t usually see it but it controls the opening and closing of the bolt when you turn the key. The lock trim varies widely according to the taste of the buyer and can range from lever pulls or handle sets to doorknobs.

The strike plate surrounds the mortise in the door frame and keeps it even stronger, thus preventing any tearing of the wood. Finally, there’s the keyed cylinder. This operates the lock. It should be noted, however, that in many countries the locking mechanism itself isn’t a keyed cylinder but a lever mechanism. However, keyed cylinders have been the mortise lock mechanism of choice in the US for many years.