Free Delivery On Orders Over £150 Next Day Delivery - Order Before 6pm 30 Day Returns

Written by Rob Lancaster

Locks – Your Frequently Asked Questions

Here at, we’re here to help you with all of your security needs. We’re also committed to making sure you have all the information you want to help you make informed decisions and get the best from your products.  

Here are some of the most frequently asked questions on the internet to help you with all your lock related questions.  

Fitting and measuring FAQs

How to change a door lock 

Whilst the procedure for removing some door locks can be complicated and almost certainly best left to a professional, some types of lock are easy to change on your own. With a screwdriver and a tape measure you can change a cylinder lock with no trouble. Check out our handy guide to cylinder locks for information on how to do it. 

How to measure cylinder lock 

Cylinder locks are easy to measure. You can measure the lock whilst it’s still in the door, by measuring the length between the door and the fixing screw located on the side of the door, underneath the cylinder lock. You can also remove this fixing screw to take the lock out of the door, and then measure the cylinder this way. You can use our guide here to help you. 

What is a lock backset? 

The measurement from the edge of the door to the keyhole. This ensures there is space to fit the lock mechanism into the door. 

This is the measurement taken from the edge of the door to the keyhole. This measurement is referred to as the backset because it’s the space required for the lock mechanism to be housed in the door. It’s also important for the locations of keyholes and handles to be measured when carrying this out. A lock with a backset will often require professional installation.  

How to adjust multipoint door lock 

There are several measurements that need to be made for a multipoint door lock to be fitted correctly. The lock backset must be measured, whilst all the locking points along the length of the door must be measured. You can also adjust the position of the strike plates on your door frame where the bolts or other locking mechanisms engage. Using a screwdriver, you can loosen the plates and reposition them so that the locking components all engage properly. A diagram with some measurements on a multipoint door lock are given below. 

multipoint door lock measurements

General Locks FAQs

How does a lock work? 

There are several variations of locking mechanisms that are found throughout the world. Usually however a lock will use tumblers or pins to move bolts in and out of locking positions.  

Lever lock – a spring loaded bolt is moved in and out of position by tumblers when aligned correctly. These are often found on mortice locks. 

Pin lock – when pins are aligned the key can be turned, removing the bolt from the door. 3, 5, or 6 pins are common, although other variations are available. These mechanisms are often found in cylinder locks.  

How to reset a combination lock 

Resetting a combination lock often involves moving the shackle to a different position and depressing it. This will happen at either 90, 180 or 270 degrees. Keep the shackle held down whilst resetting to your desired combination then release and place back into neutral position to complete the reset and finalise the new code.   

Combination Locks

What is a sash lock? 

Sash locks are quite common. Often found fitted on bathroom doors because of their functionality. They have a latch operated by a handle and often a separate key or thumb turn to lock on one or both sides. They differ to deadlocks as these do not have catches or the associated handles. 


This shows a sashlock, where the door catch is seen, as well as the fitting for the door handle


This shows a deadlock, where only the deadbolt secures the door

What are the differences between a lock and a smart lock? 

A smart lock is a more recent invention and is becoming more popular. A smart lock will use either one, or a combination of: 

These locks offer great functionality in smart homes connected via apps to phones. You can grant access to people whilst you are absent using the internet, and the lock will often also automatically engage if you have been absent from the property for a certain amount of time. With the increasing reliability in connectivity, smart locks have the potential to become more and more common in new builds. 

Are euro cylinder locks reversible?  

A double euro cylinder lock can be reversible in some circumstances. This depends on the measurements of the cylinder lock, as if the measurements on the A and B side are different lengths, then the lock may not fit properly if reversed. Additionally, the lock may only feature anti-snapping on one side. There will be a shallow groove cut into one side of the lock, a sacrificial point that indicates the anti-snap feature.  

Can you rekey a euro cylinder lock? 

Rekeying a lock is possible on euro cylinder locks. Rekeying can be done at home but a specialist kit will be required for each different brand of lock that you have in your house. Browse our selection of euro cylinder locks to find the right security solution for you. 

What sizes do euro cylinder locks come in? 

Euro cylinder locks are available in many different sizes. See our guide on how to measure a cylinder lock to see what size you need. It’s important to remember that the A and B side of your lock may not need to be the same length. It is also more likely to find 6 pin configurations in longer locks, as shorter ones cannot accommodate the same number of pins meaning they are slightly less secure.  

If you have any further questions or need any more information, do not hesitate to get in touch with our friendly and professional team here at  

Browse more articles in

Share this post

About the author

Rob Lancaster is part of the marketing department at He researches and writes content for the site, producing guides, blogs, and articles.

Customers who bought this item also bought the following: