How to Rekey a Lock: A Locksmith’s Step-By-Step Guide

Locks play a crucial role in ensuring the security and safety of our homes and possessions. However, there are situations where you may want to change the key that operates a lock without replacing the entire hardware. This process is known as rekeying, and it’s a valuable skill that every locksmith should master.

Rekeying allows you to maintain the existing lock while rendering old keys useless and introducing new ones. In this comprehensive guide, we will delve into the step-by-step process of rekeying, equipping you with the knowledge to execute this task like a seasoned locksmith. In case it is too much or if you come across an issue that is beyond you, St. Louis locksmith is there to help you.

Remove the Lock from the Door


The first step in rekeying a lock is to take it off the door. Before you start, ensure you have the necessary tools: a screwdriver, pliers, and a plug follower. Begin by unscrewing the mounting screws on the inside of the door using the appropriate screwdriver. Once the screws are removed, gently pull the lock away from the door, exposing the latch and the exterior part of the lock. Be cautious not to damage any components during this process. Next, using pliers, carefully retract the latch to release it from the strike plate on the door frame. Now, you should be able to fully remove the lock from the door. Keep track of all the parts, as they will need to be reassembled later.

Disassemble the Cylinder

With the lock removed from the door, it’s time to disassemble the cylinder. Look for a small retaining clip or ring around the cylinder’s face and use a flathead screwdriver to remove it. This step may require some patience and finesse, but once the retaining clip is off, the cylinder should easily slide out of the lock housing. Pay attention to the orientation of the cylinder as it comes out, as this will be important during reassembly. Once the cylinder is out, locate the plug follower, which is a vital tool in the rekeying process. Insert the plug follower into the back of the cylinder to guide the plug as you remove it from the housing. Gently push the plug follower until the plug comes out, exposing the lower pins and springs inside the cylinder.

Remove Existing Pins and Springs


With the plug exposed, it’s time to remove the existing pins and springs. The number of pins may vary depending on the type of lock, but most standard locks have five or six pins. Using tweezers or needle-nose pliers, carefully extract each pin and its corresponding spring from the plug. Pay close attention to the order and sizes of the pins as they come out, as they will dictate the new key pin combinations you’ll use later. As you remove the pins, place them in an organized manner to avoid mixing them up. Once all the pins and springs are removed, take a moment to inspect the plug for any debris or dirt that may interfere with the rekeying process. Clean the plug thoroughly if necessary.

Determine the Key Pin Combinations

The heart of rekeying lies in determining the new key pin combinations. Each pin in the lock corresponds to a specific cut on the key, and by changing the pins’ arrangement, you’ll create a new key that operates the lock. To determine the new pin combinations, you’ll need a key decoder, also known as a pinning chart. These charts are specific to each brand and model, and they help you identify the proper pin sizes for the desired key cut. Align the original key with the decoder and take note of the pin sizes for each cut. Now, using the new key you want to use for the rekeyed lock, repeat the process and record the pin sizes for the desired key cuts.

Insert New Pins and Springs

With the new key pin combinations determined, it’s time to insert the new pins and springs into the plug. Begin by placing the first new pin and its corresponding spring into the bottom of the plug, and continue with the rest of the pins according to the pinning chart. Use the plug follower to ensure the pins sit flush inside the plug. This step requires precision and attention to detail to ensure the lock functions smoothly with the new key. After all the new pins and springs are in place, reinsert the plug into the cylinder and slide it back into the lock housing. Make sure the plug is correctly aligned with the orientation you noted during disassembly. Reattach the retaining clip or ring to secure the cylinder in place.

Check the Key’s Functionality


Before reassembling the cylinder fully, it’s crucial to test the functionality of the new key. Insert the key and turn it to see if it operates smoothly. The key should turn without any resistance, and the lock should engage and disengage effortlessly. If you encounter any issues, double-check the pin placements and make any necessary adjustments. Repeat the process until the key operates the lock seamlessly. This step is vital in ensuring the rekeying process was successful and that the lock will work reliably with the new key.

Reassemble the Cylinder

With the key’s functionality confirmed, you can proceed to reassemble the lock cylinder. Carefully slide the plug and cylinder back into the housing, ensuring all parts fit snugly and align correctly. Once everything is in place, reattach the mounting screws on the inside of the door to secure the lock in position. Take your time during this step to avoid any misalignment or damage to the lock. Double-check that it functions correctly once it’s back in the door. The rekeying process is nearly complete, and you’re one step closer to enjoying enhanced security with your new key.

Reinstall the Lock on the Door


After the lock has passed all tests, it’s time to reinstall it on the door. Align it with the door’s borehole and carefully insert the mounting screws. Tighten the screws securely, but be cautious not to overtighten them, as this could cause damage to the lock or the door. Once it is back in place, test the key’s functionality one last time to ensure it hasn’t been affected during reinstallation.

Final Words

Rekeying may seem like a daunting task, but with the right knowledge and tools, it becomes an accessible skill for locksmiths and DIY enthusiasts alike. Remember to approach each step with care and precision, and don’t hesitate to double-check your work along the way. Rekeying not only saves time and money but also empowers you to control access to your property.