How to Rekey a Deadbolt Lock Like a Pro

Why it matters

Rekeying a lock is the process of changing the internal pins of a lock cylinder so that a new key works and the old one does not. This is a critical security measure that ensures you have total control over who has access to your home.

The primary benefit is cost efficiency: rekeying is significantly cheaper than replacing the entire lockset hardware. While a new high-quality deadbolt can cost between $50 and $150, a rekeying kit costs roughly $15 to $25 and can service up to six locks. Beyond the financial savings, rekeying allows you to "reset" your home security without the need to drill new holes or worry about matching the finish of your existing handlesets. It also provides the convenience of a "Master Key" system, where one key opens every exterior door in your house, reducing the bulk on your keychain.

How often

There is no set schedule for rekeying, as it is a situational security task rather than a wear-and-tear maintenance item. However, you should rekey your locks in the following scenarios:

• Moving into a new home: This is the most common time. Even with a new build, subcontractors often have "construction keys" that may still function.
• Loss of keys: If a house key is lost or stolen, the only way to ensure the finder cannot enter is to change the internal pins.
• A change in occupants: After a roommate moves out or a domestic relationship ends.
• Service professional access: If you have given a key to a contractor, cleaner, or pet sitter and no longer employ their services.

What you need

To DIY this project, you must purchase a rekey kit specific to your lock brand (e.g., Kwikset, Schlage, or Baldwin). The pins from a Kwikset kit will not fit a Schlage lock.

Tools & Materials

• Rekey Kit: Includes new pins, a "follower" tool, a ring remover, and new keys.
• The Current Key: You generally must have the working key to remove the cylinder.
• Needle-nose pliers: For handling tiny pins.
• Small flat-head screwdriver: To pry off C-clips.
• Clean workspace: Use a white towel or tray so you don't lose the microscopic springs and pins.

Step-by-step

The following steps apply to common residential pin-tumbler deadbolts.

1. Identify the Lock Brand: Look at the edge of the door or the key itself to find the brand name. Purchase the corresponding rekey kit.
2. Remove the Lockset: Unscrew the two long screws on the interior side of the door. Pull the two halves of the lock (the thumb-turn and the exterior cylinder) away from the door.
3. Extract the Cylinder: Use the kit’s wire tool or a screwdriver to press the retainer tab and slide the lock cylinder out of its decorative housing.
4. Remove the C-Clip: Locate the C-shaped metal clip at the back of the cylinder. Use the clip removal tool from your kit (or a flathead screwdriver) to pop it off. Keep your thumb over it so it doesn't fly across the room.
5. Insert the Old Key: Put the current working key into the cylinder and turn it about 45 to 90 degrees. This aligns the "shear line" so the cylinder can slide out.
6. Use the Follower Tool: This is the most critical step. Place the cylindrical "follower" tool against the back of the cylinder plug. Push the plug out through the front of the housing using the follower. The follower must stay inside the housing to keep the upper springs and "top pins" from falling out.
7. Dump the Old Pins: The cylinder plug you just removed contains the bottom pins. Tip it over to dump the old pins. Do not remove the follower from the housing during this time.
8. Insert the New Key: Slide the new key (provided in the kit) into the empty cylinder plug.
9. Load New Pins: Your kit will have color-coded or numbered pins. Follow the instructions in the kit to drop the specific pins into the holes in the cylinder. When the new key is inserted, the tops of all pins must be perfectly flush with the surface of the cylinder.
10. Reassemble: Push the cylinder plug back into the housing, using it to push the follower tool out the back. Reattach the C-clip.
11. Test: Turn the new key to ensure it rotates smoothly. If it binds, a pin is likely the wrong size.
12. Reinstall on Door: Place the lock back on the door and tighten the mounting screws.

When to call a pro

While rekeying is manageable for patient DIYers, you should call a locksmith if:

• You lost the "follower": If the upper pins and springs fall out of the housing, it is extremely difficult for an amateur to put them back in.
• You don't have the original key: If you cannot turn the lock to the 45-degree angle, you cannot remove the cylinder without specialized locksmith tools like a pick or a drill.
• The lock is damaged: If the lock is sticky, grinding, or the mounting holes are stripped, rekeying won't fix the underlying mechanical failure.
• High-security or Smart Locks: Digital locks or "unpickable" high-security cylinders often require proprietary tools or factory-level resets.

Safety

• Test before closing: Always test the new key while the door is open. If the lock malfunctions or jams, you are not trapped inside or locked out.
• Small Parts: This project involves tiny brass pins and springs. They are a choking hazard for pets and toddlers and are virtually impossible to find if dropped into a high-pile carpet.
• Spring Tension: Use eye protection. The upper pins are under spring tension and can occasionally pop out of the housing with significant force if the follower tool slips.

Cost

DIY Cost: $15–$25 for a rekey kit. Most kits can rekey up to 6 locks of the same brand. Professional Cost: $75–$150 service call fee, plus $15–$30 per cylinder.

If you have five locks to rekey, a locksmith may charge $250 or more, whereas a DIY kit allows you to do the same job for under $30 and about two hours of your time. Note that if you take just the cylinders into a locksmith shop (instead of having them come to your house), you can often get them rekeyed for $10–$15 per cylinder, avoiding the expensive service call fee.