What is a mortice lock?

Security is a number one priority for any building, whether it is a residential or commercial property, and whether it is continually occupied or frequently left vacant. Regardless of the activities or operations undertaken at a property, security should be considered very highly and that means choosing the right type of lock for the property.

There are many different types of lock on the market, and it can be hard to understand what would suit you best, particularly when many of them look the same. One of the most popular types of lock is the mortice lock, and in this guide we will explain what the mortice lock is, what different types there are available and how it works.

Understanding the mortice lock

A mortice lock is a type of door lock that is installed within a pocket cavity in the leading edge of a door. This pocket cavity is known as a mortice. So essentially, a mortice lock is a type of lock that is installed within the door itself, rather than being surface mounted on the door’s surface. This means a mortice lock is effectively describing how the lock is installed rather than describing how the lock is operated or what its function is.

Because the mortice lock is embedded within the door, only the faceplate and the door handles are visible, the lock itself can only be seen on the leading edge of the door.

How does a mortice lock work?

The mechanism of a mortice lock is relatively large, and looks like a type of cassette that is thin and has a metal casing. In many cases this mechanism will have a bevelled latch included in it. This mechanism slots into a mortice pocket within the door itself, and so this slot has to be created before installation. This means the door has to be a certain thickness and has to be suitably robust that it can accommodate the lock and handle a section being hollowed out of it.

Once installed, the mechanism has a space for a bolt to retreat into, plus a series of parallel levers with a bolt stop. When a key is inserted, the correct key with the right cut will align with all these levers and therefore the mechanism will be able to be rotated, which in turn will withdraw the bolt to unlock the door. The wrong key will either not fit into the keyhole at all, or will catch the levers and not align them to make the rotation and unlock the door. This process of operating the mortice lock and unlocking the door is the same regardless of the actual type of mortice lock.

What type of mortice locks are there?

There are several types of mortice lock on the market, but by far the two most common are:

• Deadlock – This uses a key alone to throw a deadbolt across the mechanism to lock and secure the door.
• Sashlock – This uses a bevelled latch and a key to operate the door, and means you don’t need to use the key to lock it or unlock it from the inside. Nevertheless, when opening the door using the key from the outside, this operates a deadbolt as above.

Within the scope of mortice locks there are what is known as 5-lever locks, 3-lever locks and 2-lever locks. This refers to the number of levers within the mechanism, and hence, a 5-lever lock offers more security than a 3 or 2-lever lock, because it is harder to pick. 5-lever locks are the standard lock most commonly used, while 3-lever locks are cheaper to buy, and are perhaps more suitable for internal doors where security risks are reduced.

Where would you use a mortice lock?

Although you would normally use a mortice lock on a wooden door, ie. a door where you can hollow out the mortice, you can install one in a metal door if a suitable cavity is created. However, because the mortice mechanism is a relatively large construction the door has to be a certain thickness, and for this reason a mortice lock would normally be used on an external door, which will be thicker and more robust than a thinner internal door.

Mortice locks can be used on internal doors where the security risk is reduced, such as in a bed and breakfast business or in a house converted into separate flats, such as student accommodation. They can also be used on a bathroom door. A mortice lock could also be used on an internal door by a business using a room for storage.

Order your mortice lock mechanism from MB Direct

At MB Direct we have a large range of different mortice lock designs, including deadlocks and sashlocks and mortice locks for bathroom doors. So check out our range and order your mortice lock online today.