How to Measure a Euro or Oval Double Cylinder
Changing or upgrading a Euro or Oval double cylinder lock can be an easy 5 minute job, with no special tools required, even an incompetent DIYer can manage this job! The hardest part of upgrading is making sure you order the correct size, cylinder locks that stick out too far from the door, can be dangerous to users and a security risk.
Firstly we need to explain some of the important parts of a cylinder lock;
Click image for a larger version
Cylinder cam - Black part normally located in centre of the cylinder, the cam turns with key and engages with lock mechanisum of the lock case.
Retaining screw hole - Screw hole used to hold cylinders in the door, also used as a measuring point.
A simple metric ruler can be used to measure a cylinder, measurements can be taken whilst cylinder is still in the door, but we would recommend the cylinder is removed for accurate sizing. Cylinders can be removed from a door by following these simple instructions.
Removing a Cylinder Lock
1 – Open the door, then remove any lock faceplates from edge of door.
2 – Unscrew cylinder retaining screw, this is found on edge of door in line with the bottom of the cylinder, usually a Phillips head screw.
3 – The key has to be used to remove the cylinder, insert key in the normal way, then apply a small amount of pressure to pull the cylinder out whilst turning the key slowly and this will allow the cam to line up with lock case and enable removal.
Once the cylinder has been fully removed from the door, measurements can easily be taken.
Place cylinder on a flat surface,
1 - Align the ruler along lower edge of the cylinder
2 - Measure overall length of cylinder
3 - Then measure distance from front of the cylinder to centre of the screw hole and centre of screw hole to rear of cylinder
4 - Make a note of all measurements, a typical cylinder size is 60mm Overall length, 30mm from front to centre screw hole and 30mm from centre screw hole to rear of the cylinder, thus giving a size of 60 30/30.
Once the new cylinder has been purchased, replacement is almost the reverse of removal;
Fitting a new Cylinder Lock
1 - Insert key into new cylinder, then turn key until cam lines up with the cylinder body.
2 - Whilst holding key and cylinder, use both hands if needed, insert cylinder into the door.
3 - From edge of door, slot retaining screw into screw hole and screw into cylinder.