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How to measure a cylinder lock

How to measure a cylinder lock

A cylinder lock is a lock mechanism that uses pins of various lengths to help lock the lock by the incorrect key. The first main advantage to a cylinder lock, also known as a profile cylinder lock or euro, is that the cylinder can be changed without altering the bolt work hardware.


The first know pin tumbler lock was found in the ruins of the Palace of Khorsabad in Iraq, but the basic principles of the pin tumbler lock may date back as far as 2000 BC in Egypt.

Changing A Cylinder Lock

Looking at changing your cylinder lock but not sure where to start? Don't worry, Total Safes are here to help and advise on what to do next.


Remove the old cylinder from the door. Removing the screw that holds the cylinder into place. This can be done by opening the door and removing the retaining screw. The cylinder will become loose


Once the screw has been removed, then insert your original key and turn the key to 10 to or 10 past 12, pulling the key towards yourself. The cylinder should pull out easily.



Internal Side "A Side"
Measure from the face of the inner side to the centre of the screw hole.
External Side "B Side"

Measure from the centre of the screw hole to the face of the key side


Total Size
If the Total size = A side + B side, then order the size
required (i.e. 50/50)

Once you have measured your cylinder lock, the next task is to buy a new cylinder for your door. Total Safes have many different cylinder locks such as Double Euro Cylinder LocksDouble Oval Cylinder Locks and many more.


If you would like more information on locking types and how find the right lock for you, then get in touch with us today. You can email us at, or you can call us on 0161 819 6888


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