How to Measure a Mortice Lock

Here at Lock Shop Direct we stock over 100 different mortice locks and latches. To browse the full range please select here.

However we know that measuring a mortice lock can sometimes become confusing. This short video shows how to correctly measure the five different parts of a Mortice Lock so you can buy the right sized replacement lock first time:

The diagrams below show how to check the sizes required in order to ensure you order the correct sizes. As shown below there are 2 main parts to a mortice lock these are the case and the forend.

1. Backset
The backset is measured by placing a tape measure or ruler from the center of the keyhole to the forend of the mortice lock. Please see the demonstration below:



2. Case Width
The width of a mortice lock is measure by measuring the distance between the edge of the case and the edge of the forend. Please see demonstration below on how to do this:



3. Case Height
The case height of a mortice lock is measured by measuring the distance between the top left corner of the case to the bottom left corner of the case. Please see the demonstration below on how to do this:



4. Forend Length
The forend length of a mortice lock is measured by measuring from the top right corner of the forend to the bottom right corner of the forend. Please see the demonstration below on how to do this:



5. Forend Width
The forend width of a mortice lock is measured by measuring from the top left hand corner of the forend to the top right hand corner of forend, Please see demonstration below on how to do this:



Click here to view our full range of Mortice Locks including 2, 3, 4 and 5 lever mortice locks, tubular latches and mortice latches.