How does a mortice lock work?

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How does a mortice lock work

In this post on the blog, we’re going to be considering briefly the question – how does a mortice lock work?

What is a mortice lock?

First things first, what is a mortice lock? Basically, it’s a type of lock that is installed into the edge of a door and consists of a mechanism that fits into the interior of the door. These locks are typically found on exterior doors, as they require a certain thickness in order to be installed.

If you’re looking for a more detailed answer, check out or other post that answers this question here.

How a mortice lock works

The mechanism of a mortice lock contains a space for the bolt to retract into, as well as a series of levers that are attached to the rear of the bolt through a small piece of metal called a bolt-stop. The design of the key’s cut is specifically made to match the internal levers of the corresponding lock. When the correct key is used, the levers align and the entire mechanism can be rotated to extend and withdraw the bolt. However, if the wrong key is utilized, it either will not fit into the lock or will not properly engage all of the levers.

In addition to these components, a mortice lock also includes a strike plate, a piece of metal surrounding the mortice that helps the bolt fit smoothly into the door, and a faceplate, which is a separate piece of metal that attaches to the door and faces the strike plate. There are also escutcheon plates around the handle that serve no functional purpose, but rather are there for aesthetic reasons. If you’re looking for tips on how to measure a mortice lock, we’ve written an article that you can check out here.

So there you have it – a brief look at how a mortise lock works. We hope this helps give you a better understanding of how mortice locks work but as always, if you’ve got any further questions or you need some help with a mortice lock that’s stuck, don’t hesitate to get in touch.

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David is the owner of Locksmiths of London and he's passionate about improving home security.

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