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How to Change the Cylinder in a Door Lock

This article is a collaborative effort, crafted and edited by a team of dedicated professionals.

Contributors: Muhammad Baballe Ahmad, Mehmet Cavas, Sudhir Chitnis, and Zhen-ya Liu.

✓ Verified & Tested Information

A quick and easy guide on how to change the cylinder in a door lock .


If you’re planning on changing the cylinder in a door lock, it’s important to ensure that you have all the necessary materials and tools. There are certain tools, such as a screwdriver, that are required for this process. Additionally, you will need a replacement cylinder which should match the existing one in size and design. Make sure that you research the type of cylinder that is compatible with the door lock before you make a purchase.

Gather necessary tools

Before embarking on a project to replace the cylinder in your door lock, be sure to gather all necessary tools. Depending on the door lock, you may require a flat-head screwdriver and/or an Allen wrench; a screwdriver of the appropriate size; and either a special rekeying kit or individual key pins. Even if you are installing new parts, check to ensure that all parts are included in the purchase before proceeding. Also make sure that your workspace is adequately lit and free from distractions so that you can focus on the task at hand. Gather all of these items ahead of time to ensure that your process runs as smoothly as possible.

Remove the existing cylinder

To remove the existing cylinder from your door lock, you will need to get it in a locked position. To do this, insert your key and turn it clockwise until the cylinder is locked. Once it is locked, look for two small pins on either side of the locking mechanism. Take a small flat head screwdriver and apply pressure to these pins. As you are pressing down on these pins, use a cloth to help protect them from becoming damaged. At the same time, pull out on the cylinder of your lock using gentle force until it comes free from its place within the door or lockset housing. You may also need to use a pair of needle nose pliers to grab onto the edge of the cylinder and gently twist as you pull outwards so that it can be removed easily.

Installing the New Cylinder

Changing out the cylinder in a door lock can be an easy process to do for a homeowner. After you have determined the right size cylinder and have purchased the right one, you can begin the installation process. Before getting started, it is important to turn off the power to the door lock so that you do not shock yourself. Once that is done, you can begin to install the new cylinder.

Measure the door thickness

Before getting started with the installation process, it is essential to measure the thickness of the door to determine what size cylinder is needed. A blank cylinder that is too large may not fit or may render some components of the door lock unusable while a cylinder that is too small may not be secure.

Furthermore, take note of the face plate – some locks require different size cylinders depending on how it is mounted onto the door. Typically for cylinders fixed directly into wood doors, the face plate will be flat and can measure between 20mm – 22mm in width and 51mm – 76mm in length. For bolts fixed from both sides (doors with larger gap), a curved plate will be available which can measure 24mm – 26mm in width and 80m – 92m in length.

Once you have taken these measurements, you are now ready to select a suitable new cylinder and begin installing it into the door lock.

Select the correct cylinder size

Before purchasing and installing a new cylinder, you must make sure you have the correct size. Measure the cylinder diameter (width of the cylinder hole) and verify it is suitable for your door. If you measure the inside of your lock, typically this is between 19mm and 21mm in size, however this is not always true and can vary depending on type of lock. Manufacturers may state their recommended sizes in their product specifications as well. Once you have measured or identified the right size for your lock, you can select a new cylinder of compatible size when purchasing online or in-store. Keep in mind that most cylinders come with two keys; some types of cylinders come with even more – such as three to five keys for enhanced security.

Install the new cylinder

Once you have the tools and the necessary parts to install the new cylinder, you can begin the project. Total project time should be 30 minutes or less.

Before you begin, inspect both the interior and exterior of your door. Make sure there isn’t any damage that could interfere with a successful installation. If your door has sustained any damage, repair it with an appropriate repair product before installing the new cylinder so that it fits securely in place.

Next, use a screwdriver to unscrew and remove the screws that hold the existing cylinder in place. Carefully unhook any cables and then pull out the existing cylinder lock. Next, take the new cylinder lock and push it into place until it is fully inserted into its housing on both sides of the door frame.

Securely screw in all screws firmly in order to lock your new cylinder in place through both of its housings on each side of your door frame – top, middle and bottom screws for each side if applicable depending on your design. If necessary, re-hook up any cables from prior structure before installing a new one within appropriate housing slots using pliers or other tools if needed for added stability when re-hooking cables from prior connections from previous structure when installing an updated housing into respective slots for extra coverage needs. All secure cable connections should wrap around respective cylinders for secure placement when applicable for added security needs with regards to future plans as needed based on assessment criteria per case file escalation requests as carried out by local authorities due to contractual obligations within area vicinity range as agreed upon by responsible governing citing body as estimated at time of negotiations per stated policy concerns according to written agreements ratified by said agencies moving forward as estimated within term limits set forth by offer clause extensions approved by legal correspondents at time mark request hereby acknowledged whenever notice has been duely acknowledged through activation proceedings duly signed sealed delivered etc…

Finishing Touches

Once you’ve completed the process of changing the cylinder in your door lock, you can move on to the finishing touches. This includes making sure that the cylinder fits snugly into the door frame. You should also make sure to use the right screwdriver and any other necessary tools to ensure the cylinder is properly secured in place. Additionally, you should make sure the latch and strike plate are properly aligned. Following these steps will complete the process and ensure your door lock works as it should.

Check the cylinder for proper fitment

Once the cylinder has been removed, it’s important to check the fitment of the new cylinder. Many cylinders come with a slotted cap and two plastic pieces. Place these two plastic pieces in each end of the cap. This will help you determine if the new cylinder is sufficiently inserted before you go ahead with installation. Check that there is no interference between the plastic pieces and the sides of the hole where the cylinder will be placed. This interference could be caused by debris or a poor fitment with one or both of them being too large or too small for its designated hole in the door lock mechanism. Make sure that you also check that none of these plastic pieces are obscuring any important parts thus reducing their ability to function efficiently.

Reassemble the lock

Once you’ve reassembled the cylinder and updated or installed new components, it’s time to reassemble the lock. Begin by gently inserting the cylinder back into the lock housing. Rest assured that you don’t need to use any force as everything should fit back together quite easily, provided that all parts are compatible with one another. Secure the cylinder within the lock housing using a screwdriver and screws provided in your repair kit, if necessary.

Next, place the trim on top of the cylinder and replace any screws used in securing it. Finally, replace any connecting components such as wires or cables required to ensure proper lock operation. It’s a good idea to check all plastic connectors for wear before replacing as some may have become brittle over time from sun exposure or exposure to moisture. Once everything is reassembled and connected, check for proper operation before closing up any exterior panels.

Test the new cylinder

Once the new cylinder has been inserted into the door lock, it is necessary to test that it operates correctly. With the key in the lock, turn the cylinder several times to ensure that it moves smoothly and does not get stuck or jammed. Additionally, make sure that when you turn the key in each direction, it causes the bolt of the door lock to move back and forth accordingly. If you are satisfied with its performance, you can reassemble the rest of your door lock and reinstall everything correctly. Finally, use a screwdriver to tighten any screws on your door lock that may have become more loose over time due to wear and tear.

It is essential to properly check if your newly installed cylinder functions correctly before finally closing up your door lock. Taking a few extra minutes at this stage can help save potential trouble down the road with a faulty cylinder or an unsecured home.

How to Change the Cylinder in a Door LockCheckout this video:

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