D.E.S Locksmiths Left Column Cap Left Column Cap


How to measure a cylinder

With the ever increasing fitment of products like UPVC doors, it has become easier to replace the cylinder. The following helps you to identify and replace like-for-like.

If in doubt, either bring in the lock or draw around it and bring that into the shop, we will then find you a replacement.

First identify whether you have a Euro or Oval Cylinder:

Euro is shaped like this: Euro Profile Cylinder Shape

Oval is shaped Like this: Oval Profile Cylinder Shape


If you need to change the cylinder like-for-like, then you need to remove the lock and take two measurements (A & B) as follows:

How to measure a Euro

Be sure to remember which way you removed the lock and if you have a thumb turn, please note which side, A or B this is on. There are many different sizes and offsets so we need to know the details if we are to supply a direct replacement.

Measure side A in mm and make a note, then measure side B and make a note. As a ‘double check’ measure the complete length and add A & B together.  These should equal the same amount.

Examples of the sizes most commonly found are A 35mm and B 35mm or A 45mm and B 45mm. These are often shown as: 35/35 or 45/45.

If you only have half of this type of lock, then measure from front to back and make a note in mm of the size. You require a “half Euro” or “half Oval”.


Finally, note whether you would like a Brass or Silver finish.


Flush Fit

Please note that if the lock ‘un-necessarily’ sticks out by anything over 5mm then you need to reduce the size of the lock accordingly.