Cylinders

How do I measure a cylinder?

Measuring a cylinder

A door cylinder is measured by the distances from either end of the cylinder to the centre of the screw hole, labelled A and B on the diagram. The size of the cylinder is then said to be A-B, with the smaller size preceding the larger.

For example, if the distance A were 30mm and the distance B 45mm, the size of the cylinder would be 35-45.

What is a euro profile cylinder?

A Euro profile cylinder is one which has a profile shaped like a traditional keyhole. This type of cylinder is operated by a key on both sides. These types of cylinders are the most common type of cylinder.

What is an oval profile cylinder?

An oval profile cylinder has an oval shaped profile. It works in an identical manner to the euro profile cylinder. These types of cylinders are more commonly used on mortice locks on aluminium or wooden doors.

What is a thumb turn cylinder?

A thumb turn cylinder is similar to a Euro profile cylinder except that one side is operated by a knob and the other by a key. This means that the door can be opened and locked from the inside without a key, but on the outside a key is required.