Euro cylinders: how to measure them from Clement Stilwell's blog

How a locksmith would go about picking cylinder lockHow a locksmith would go about picking cylinder lockTaking measurements for a new door or replacing an old cylinder lock is a quick and simple procedure.

To determine which measures to take based on your specific scenario, look to the diagram. A cylinder with two equal lengths is required when the dimensions of A and B are the same. A cylinder with an offset is required if they are different.

1. The first step is to measure an existing cylinder lock.

No need to remove the present lock from the door in order to take measurements for a replacement euro cylinder! This can be accomplished by starting at step 3 of the guidelines provided below: Additionally, you can take the lock apart to get a measurement. This can be accomplished by beginning with step 1. If your lock requires a key to be opened, you'll also need it.

2. Depress the cylinder's release button

A central screw, which is placed on the facing edge of the door, holds the cylinders in place when they have been installed. To release the cylinder, unscrew this screw.

3. Take the cylinder out of the equation!

Depending on whether your lock requires a key, you will need to insert and spin the key to check that it is aligned with the cam and flush against the cylinder. Then enter the key into the cylinder from one end, turn the key roughly 45 degrees left or right (depending on which side of the key you insert) and pull the cylinder out of the keyhole.

If your lock is a keyless thumb-turn euro cylinder, proceed to step 1 and simply turn the thumb-turn slightly while carefully taking the cylinder out of the lock.

Read more: How a locksmith would go about picking cylinder lock

4. Take the cylinder's diameter into consideration.

You will need to take two measurements in order to accurately measure the cylinder lock. Start by taking a measurement from one end of the cylinder to another and dividing it by two. This measurement is known as exterior size to center (A). The method should be repeated for the other side in order to get the internal size to be in the center (B).

5. Do not forget to check your work twice before submitting it.

If you want to be sure your calculations are accurate, measure the total length and make sure it equals the sum of A and B

A new door is being measured up.

Taking measurements for a new door requires measuring the width of the door and any door furniture such as handlesets or escutcheons that will be installed on the door.

1. Take a measurement from the outside to the center of the outside.

You should take a measurement from the outside border of the door, including any furniture, to its center point (see illustration). Measurement A is as follows:

2. Take the internal size from the center out and multiply it

Then, to obtain dimension B, take a measurement from the inner border of your door, including the furniture, to the center of your door.

3. Measure the entire length to make sure everything is in working order before you start.

Take measurements from the outside edge of the door to the inner edge of the door, including any furniture, to double-check your measurements. You should be able to add A and B together to get an overall length that equals the sum of the two.