How to Measure a Cylinder Lock
If you find yourself needing to install or replace a cylinder lock, you’ll first need to obtain some measurements of the lock in order to ensure that it will fit correctly with the door you are fitting it into. In this helpful guide, we’ll explain how you can measure the size of a cylinder lock while it is currently in the door, as well as when it is on its own, out of the door. The methods discussed below can be used on both standard euro cylinder locks as well as the thumb turn variation.
MEASURING A CYLINDER LOCK WHEN IT IS IN THE DOOR
Being able to measure a cylinder lock whilst it is still in the door is very useful in scenarios where your current lock needs replacing, and you are shopping for a new one but are unsure exactly what size you need. There are two measurements that you will need here: the distance between the cylinder lock retaining screw and the projection of the handle plate on both the inside and outside of the door. This may sound confusing, so we have created a diagram that explains what exactly these measurements are!
Z is the location of the cylinder lock retaining screw
X is the distance between the retaining screw and the outside handle plate (external length)
Y is the distance between the retaining screw and the inside handle plate (internal length)
HOW DO I KNOW WHAT SIZE CYLINDER LOCK I NEED?
Once you have obtained these measurements, round them up to the nearest 5mm and this will give you the size of cylinder lock that you will need for your door. Internal and external length are the terms that we use to describe these two measurements when referencing our cylinder lock products. So for example, let’s say your internal length rounded up measures at 40mm and your external length at 45mm, you will need a 40mm x 45mm 85mm euro cylinder lock.
MEASURING A CYLINDER LOCK
Measuring a cylinder lock on its own is slightly simpler than the method mentioned above. You’ll need to take the same two measurements but this time, instead of measuring from the retaining screw point to the projection of the door handle plate, it will be from the retaining screw point to the edge of the lock, excluding the projection of the key insert. If you are measure for a thumb turn lock, do not include the thumb turn in your measurements either.
If you have any further questions about cylinder locks or aren’t quite sure which one is right for you, please feel free to get in touch!
