How to Rekey a Lock

Rekeying a lock is the process of changing the internal lock tumblers so an existing key no longer works and only a new key can open the lock. Rekeying is an easy and cost-effective way to upgrade home security or restrict access without replacing the entire lock. With a few tools and some patience, homeowners can rekey most standard pin and tumbler cylinder locks in about 15-30 minutes.

When to Rekey a Lock

There are several common situations when rekeying an existing lock is preferable to replacing it:

Moved into a new home – Previous owners likely had copies of the keys, so rekeying locks prevents unwanted access by those keys.
Lost or stolen keys – Rekeying is faster and cheaper than replacing locks. It ensures lost or stolen keys can no longer open the lock.
Lock doesn’t match other locks – Rekeying can make all the locks on exterior doors use the same key for convenience.
Distrust previous user – Rekey when someone you don’t fully trust had access, like a roommate, neighbor, or contractor.
Upgrading security – Rekeying upgrades a standard lock to be more pick and bump resistant.

Rekeying a lock is a DIY project for most standard cylindrical pin tumbler locks like those found on exterior doors and common interior doors. Other types of locks like high security locks, car locks, combination locks, and electronic locks require professional rekeying.

Rekeying requires rearranging the pin tumblers inside the lock cylinder. Follow these steps to successfully rekey a lock:

Things You’ll Need

New lock tumblers and keys – Buy a rekeying kit with several new tumblers and keys. Kwikset, Schlage, and American Lock are common brands.
Lock cylinder removal tool – A special tool unscrews the cylinder from the door. A flat head screwdriver can also work.
Lock lubricant – Don’t skip lubricating! This helps the lock slide smoothly when inserting or removing keys.
Pinning tweezers – Allows you to grip, remove and insert tiny tumblers.
Flat head screwdriver – Necessary for prying off the cylinder.
Hammer – Sometimes gently tapping helps remove a stuck cylinder.
Patience – Rekeying takes dexterity and focus. Expect the job to take 15-30 minutes.

Prep Steps

Rekeying goes smoother when taken slowly and methodically. Avoid frustration by following these prep steps:

Watch an online tutorial to understand the full process before starting.
Clear the table where you’ll work. Have all tools and materials neatly laid out.
Make sure there’s adequate lighting. Use a magnifying glass if necessary.
Check that no small children or pets are underfoot to prevent losing tiny pieces.
Have the new tumblers and keys handy to test the rekeyed lock immediately.

Removing the Cylinder

The cylinder contains the tumblers and needs removed from the lock body before rekeying. Follow these steps:

Insert the current key and turn slightly as if unlocking the door. This raises the tumblers to their highest position.
Insert the cylinder removal tool into the notch at the cylinder’s base and turn gently counterclockwise. The cylinder should unscrew from the door edge.
Twist a large flat head screwdriver into the cylinder notch for extra leverage if unscrewing by hand alone doesn’t work.
If needed, place a block of scrap wood against the cylinder base and gently tap the screwdriver with a hammer. Don’t dent the cylinder.
Once unscrewed, slide the cylinder out. Keep the key inserted so the tumblers stay raised and don’t fall out.

Removing Original Tumblers

With the cylinder removed, pop out the current tumblers with these steps:

Spray lubricant into the cylinder’s keyway. Generously lubricate any sticky tumblers.
Insert the current key and turn slightly like unlocking the door. Keep it in this position.
Starting from the rear, use pinning tweezers to grasp and lift each tumbler just enough to clear its side-notch.
Pull straight up to slide the tumbler out. Take care not to bend or drop the tiny tumblers.
Place the old tumblers in their original order on a clean surface. This helps with reassembly.

Inserting New Tumblers

Insert the new tumblers into the cylinder in this sequence:

Refer to the new key’s code card to identify the correct new tumblers. Locate the tiny number engraved on each tumbler.
Starting from the rear again, insert the new numbered tumblers in sequence according to the key code. Gently push down until the notch catches to hold it in place.
Check all tumblers are oriented correctly and seated firmly at the same height. Gently shake the cylinder to confirm.
Test the new key in the cylinder. It should insert smoothly and the cylinder should turn easily when the key is rotated.

Reinstalling the Cylinder

The final steps are reversing the disassembly:

With the new key still inside the cylinder, insert the entire cylinder back into the door’s edge.
While gently pressing the cylinder flush against the lock, turn it clockwise to thread the cylinder back into place.
Ensure the cylinder is correctly aligned and fully threaded in before trying to turn the key.
Test that the newly rekeyed lock opens smoothly by unlocking and locking it a few times.
Check that other keys, like the old one, no longer unlock the rekeyed lock.

With a bit of patience, rekeying a lock is an accessible DIY security upgrade. Just take it slow and follow each step carefully. And remember to make spare copies of the new key!

Tips for Easier Rekeying

While rekeying is a straightforward process, little things can make the job easier. Keep in mind these tips:

Buy a quality brand rekeying kit. Cheap tumblers can bend or jam.
Choose a lock cylinder with an open back. The back plug pops off for easy access.
Apply steady, gentle force when removing stuck cylinders. Avoid damaging the cylinder or door.
Lay a towel down. This catches fallen tumblers and protects the cylinder’s finish.
Have someone else hold the key in place when removing or inserting tumblers. Four hands are better than two!
Take a picture reassembling for reference. It’s easy to forget the tumblers’ order halfway through.
Label your new keys immediately to avoid mixing them up later.
Consider replacing old, extremely stubborn cylinders instead of rekeying them.
Upgrade to a new high-security cylinder if the current one is heavily worn or damaged.

With practice, you’ll gain confidence and rekey locks more efficiently each time.

Rekeying Different Lock Types

While most pin and tumbler cylinder locks can be DIY rekeyed, other lock types require a professional locksmith:

High Security Locks

These include locks with special designs like:

Disc tumbler locks – Key lifts a row of discs to different heights.
Slider locks – Key pushes sliding bars into alignment to open.
Magnetic locks – Powerful magnets move when the key is inserted.
Sidebar locks – Small side pins interact with cutouts in the key blade.

High security locks require professional disassembly and rekeying. Attempting to DIY rekey risks permanently damaging these sophisticated mechanisms.

Car Locks

Keys have transponder chips that connect electronically with the ignition. Only professionals can program new keys and rekey the lockset.

Combination Locks

Combination locks open by turning numbered dials to the correct sequence. They can’t be rekeyed, only reset to a new combination. This requires safely decoding the lock first.

Electronic Keypad & Smart Locks

These locks open via key codes or wireless signals, not a traditional key. A professional is required to reprogram electronic access on digital locks.

While high security and electronic locks offer advantages, their complex nature makes professional rekeying a must.

How Rekeying Differs From Changing Locks

For many homeowners, rekeying is preferable to a full lock change. Here are some key differences:

Lock Mechanism

Rekeying – The original lock body stays intact. Only the plug containing tumblers is replaced.
Changing locks – Old locks are fully removed and replaced with brand new locksets.

Installation

Rekeying – No new mounting holes need drilled. The lock uses the existing bolt holes.
Changing locks – New bolt holes usually must be drilled to install replacement lock bodies.

Cost

Rekeying – Only requires buying a rekey kit for around $10-$15 and tools if needed. Labor is free if DIY.
Changing locks – A full replacement lockset costs $25-$150 for each lock, plus professional installation fees.

Security

Rekeying – Tumblers are upgraded but the old lock body remains. Provides moderate boost in security.
Changing locks – Brand new high-security locks provide maximum security by preventing picking, drilling, and bumping attacks.

Convenience

Rekeying – Keeping the existing lock body avoids hassles of drilling new bolt holes and refitting doors.
Changing locks – No need to meticulously replace tiny tumblers, just swap out the old for new.

Consider your specific needs to decide if rekeying or full replacement better fits the situation.

Preparing to Rekey a Lock

Proper preparation is key to smooth sailing when rekeying a lock yourself. Avoid frustration by gathering these supplies before starting:

Rekeying kit – Comes with tumblers, new keys, code card, and sometimes tools. Match brand to your current locks.
Lubricant – A must for sticky, corroded locks. Choose graphite or spray lubricants designed for locks.
Lock cylinder wrench – Special tool unscrews the cylinder. A large flathead screwdriver can work too.
Pinning tweezers – Precision tweezers ensure grip on tiny tumblers for easy handling.
Rags and towels – Keep your workspace clean and catch any dropped tumblers.
Flashlight – Good lighting helps spot tiny serial numbers engraved on tumblers.
Magnifying glass – Makes it easier to handle minuscule parts if your eyesight isn’t perfect.
Eye protection – Safety glasses prevent injury if cylinder suddenly pops free.

Thoroughly reading the kit instructions is another key prep step before rekeying. Understanding the full process in advance makes the job less daunting.

Step-by-Step Guide to Rekey a Lock

Follow these detailed steps to successfully rekey a standard cylindrical lock:

Remove Cylinder

Insert old key and turn slightly as if unlocking. This raises tumblers.
Insert cylinder wrench into notch at cylinder’s base. Gently turn counterclockwise.
Unscrew cylinder fully and slide out, keeping old key inserted.

Remove Old Tumblers

Spray lubricant into cylinder’s keyway.
Insert old key and turn slightly. Keep key in.
Starting from rear, lift each tumbler enough to clear side notch.
Pull up gently to remove tumbler. Place in order on clean surface.

Insert New Tumblers

Refer to key code card to identify each new tumbler.
Starting from rear, insert in order per key code.
Press gently until notch catches to hold tumbler in place.
Ensure tumblers sit flush at consistent height.

Reinstall Cylinder

With new key still inserted, slide cylinder back into door edge.
Thread cylinder clockwise into place while gently pressing flush.
Ensure cylinder is fully threaded in before attempting to turn key.
Test newly rekeyed lock functions smoothly.

Take it slow and work carefully when handling small pieces. With practice, you’ll gain confidence rekeying locks efficiently.

Common Rekeying Questions

Rekeying locks for the first time can raise questions. Here are answers to some frequently asked questions:

Do I Need Any Special Skills or Experience?

No prior skills are required, only patience and a gentle, steady hand. Anyone can learn to rekey basic locks after reading instructions. Practice develops confidence.

What Tools Do I Need for Rekeying?

A rekeying kit provides tumblers and key. You’ll also need a cylinder wrench, pinning tweezers, lubricant, flathead screwdriver, and rag.

How Long Does it Take to Rekey a Lock?

Expect rekeying to take 15-30 minutes per lock. Removing sticky cylinders can add time. Rekeying gets faster with experience.

Can I Rekey a Lock Without the Original Key?

Unfortunately no. The original key is required to rotate the cylinder and raise tumblers for removal.

Where Can I Buy Rekeying Kits and Tools?

Hardware stores sell rekeying kits and tools. Find your lock brand for proper fit. Online retailers offer kits too.

How Many Times Can I Rekey a Lock?

A lock cylinder can generally be rekeyed 2 to 3 times before needing replacement. Heavily worn cylinders rekey less.

Will Rekeying Prevent Bumping Attacks?

Yes, upgrading standard tumblers to spool pins provides significant bump resistance and improves pick resistance too.

Don’t hesitate to rekey if it provides peace of mind and beefs up security!

Rekeying Cost Comparison

One major benefit of rekeying over fully replacing locks is cost, but several factors affect the total:

DIY vs Professional Rekeying

DIY: Around $15 per lock for kits.
Professional: $50+ per lock for labor, mileage fees.

Lock Type

Standard cylindrical: $8-$15 for DIY rekey kits.
High security: $15-$40+ for professional rekeying.

Number of Locks

A few locks: DIY for $15-$50 total.
Whole house: Potentially hundreds professionally.

Extra Costs

New tools – If lacking cylinder wrench, tweezers, etc.
New compatible locks – For exterior doors with incompatible keyways.
New strike plates – If cylinder and strike plate misalign after rekeying.

For entire houses, rekeying costs can add up. But for a few standard locks, DIY rekeying is very affordable.

When to Call a Professional

While rekeying standard residential pin and tumbler locks is a DIY job, other situations require a professional:

Commercial, industrial, or high-security locks. The complexity requires experience.
Rekeying a home with many non-matching locks. Time savings outweigh DIY trial and error.
Historic locks you want preserved. Professionals have proper delicate tools.
Locks too corroded or damaged for DIY removal of cylinders.
An immediate security threat like lost keys. Professionals can rekey fast.
Lacking the dexterity, time, or patience for fiddly DIY rekeying.
Unsure of the brand or internal design. Professionals identify mechanisms.
Large number of locks make DIY costs excessive. Paying a pro saves money.

Watch for frustration when tackling DIY rekeying. Hiring a professional locksmith is a smart choice if the situation calls for their expertise.

Improving Home Security With Rekeying

Beyond just convenience, rekeying locks boosts home security in several important ways:

Revoking Key Access

Rekeying ensures any lost, stolen, or duplicated keys no longer grant access. This eliminates a major security vulnerability.

Restricting Previous Entry

Rekey when moving into a new place or after guests or contractors visited. This fully rescinds their access.

Enhancing Physical Security

Upgrading to high-security tumblers like spools resists lock picking and bumping physical attacks.

Establishing Master Key System

Rekey locks to a master key for homeowners, while a sub-master key limits access for kids or cleaning staff.

Symmetry With Existing Locks

Rekeying unmatched exterior locks establishes one master key for convenience without replacing every lock.

Cost Savings Over New Locks

Rekeying only replaces lock innards. New locks add expenses for hardware and professional installation.

Don’t underestimate the security advantage rekeying provides! A simple tumbler upgrade keeps homes safer.

How Rekeying Differs From Changing Lock Combinations

Rekeying a standard lock differs from changing the combination on a keypad or combination lock:

Method

Rekeying – Rotates mechanical tumblers inside a cylinder to new positions.
Combo change – Uses a different ordered sequence of numbers or letters to release the locking mechanism.

Skill Level

Rekeying – Involves removing lock cylinders and replacing small pieces. Intermediate DIY skill.
Combo change – Simply inputting a new combination code. Doable for anyone.

Security Level

Rekeying – Higher security against illegal key duplication. Vulnerable to picking unless high-security tumblers added.
Combo change – Susceptible to guessing or watching