How to Change a Door Lock

Homeowners may choose to have the ‘locks changed’ for security reasons when moving into a new property or if keys get lost. Here’s what you need to know if you’re changing the locks on your front and back doors.


Only the euro cylinder needs to be changed as this is the part that interacts with a key. The euro cylinder features a classic euro shaped keyhole which operates a lock bolt retained within a case.


There a two types of euro cylinder locks; one with a key hole on each side and one with a thumbturn on one side and a key hole on the other side.


The most common type that people search for is a double euro cylinder lock which enables you to lock the door from both sides by use of a key. This type of lock is an ideal solution to replacing or updating your door security on the external doors of your property.


How Euro Cylinder Locks Work


An internal cam mechanism rotates in the lock by the rotation of the inserted key. As you turn the key, the cam rotates and moves the lock bolt, thus locking and unlocking the door. Also known as a pin tumbler lock, a euro cylinder is located through the lock case and fits securely with a fixing bolt from the edge of the door.


Size is Essential


The new replacement euro cylinder will need to have the same dimensions as the existing one that you’re switching out. A cylinder that sticks out too far on the outside will make your home vulnerable to burglary so it’s important to get the correct measurements.


The length of a lock required varies from door to door which is why we offer a variety of split sizes to suit all installation requirements.


Euro Cylinder Lock 35 35 Anti Pick Anti Drill
Euro Cylinder Thumbturn 35 35 Anti Pick Anti Drill


How to Measure a Euro Cylinder


There are two ways to take measurements; either in the door or out of the door. You can take measurements of your existing lock without removing it; simply take your ruler and open the door. Looking at the depth of the door, measure from the middle of the centre screw to the end of the keyhole face on each side of the door. Take the measurement in millimetres.


If you’re measuring the cylinder lock outside of the door, then you will need to measure the same points as outlined above.


Now that you have your measurements, you can then search for the double euro cylinder in the correct size to replace it.


We also offer thumbturn cylinders. This type of lock is primarily used on the front doors of residential apartments, student rooms and bedrooms in house shares where additional security is required. These specific living spaces do not open out to the exterior of your property. Featuring a key lock on one side of the door and a thumbturn on the other, allowing quick and easy exit in the event of an emergency.


All our double euro cylinder locks offer an attractive dual finish to suit every style of door furniture. Our euro cylinder locks feature 6 hardened steel pins with anti-pick and anti-drill technology to maximise your home security. Each euro cylinder lock is supplied with a fixing screw for installation and 3-5 keys, we also provide cylinders that are keyed alike so that the keys supplied can operate multiple cylinder locks.


If you’re unsure or need a little assistance, then contact us, we’d love to chat. Our award-winning Customer Service team have great expertise and will be more than happy to help.


We hope to inspire your home improvement projects and offer a variety of high-quality products that excel in both aesthetic and performance. If you love all things interiors and style, check out our previous blogs and be sure to visit our Pinterest for more inspiration!