How To Rekey a Lock: A Comprehensive Guide

Rekeying a lock is a practical way to improve your home’s security without replacing the entire locking unit. This process changes the lock’s internal mechanism so it works with a new key and blocks access from old keys. Whether you recently moved, lost your keys, or want to upgrade your home’s security, this guide explains how rekeying works and provides tips from This Old House experts on when to handle the job yourself or hire a professional.

Understanding Lock Rekeying

Lock rekeying is the process of altering a lock’s internal components to work with a new key while keeping the existing lock hardware. This involves changing the pins or wafers inside the lock cylinder, which are the parts that interact with the key to allow it to, or prevent it from, turning. Rekeying is often more cost-effective and less invasive than replacing the entire lock, especially when the lock is still in good condition.

When To Rekey vs. Replace a Lock

Deciding whether to rekey or replace a door lock depends on several factors. Below, we’ll explore situations where rekeying or replacement is better.

Ideal Situations for Rekeying a Lock

Rekeying is often the best choice in the following scenarios:

• After a break-in attempt
• Ensuring all locks work with one key
• Lost or stolen keys
• Moving into a new home
• When locks are still in good condition

Times Where Lock Replacement Is Necessary

It’s best to change the entire lock in the following situations:

• Changing the door hardware’s style or finish
• Locks that are outdated or damaged
• Upgrading to a more secure lock type
• When the lock cannot be rekeyed

We recommend replacement if your lock shows signs of wear or damage, or if you want to upgrade your security. In the how-to video below, This Old House general contractor Tom Solva explains how to change locks on a new home.

Pro Tip: Silva also recommends installing a lock that allows you to rekey without removing it from the door. These locks include a pin from the manufacturer that relaxes the lock’s tumblers, which allows you to set them to any new key that fits inside the keyhole.

Tools and Materials Needed for Rekeying a Lock

To rekey a lock, you’ll need the following tools and materials:

• Flathead screwdriver
• Key gauge (optional)
• Needle-nose pliers
• New keys
• Rekeying kit (specific to your lock brand)

A rekeying kit typically includes new pins, springs, and a tool for removing the cylinder plug. Ensure you buy a kit that matches your lock’s brand and model.

Step-by-Step Process for Rekeying a Lock

Rekeying a lock involves several precise steps. Here’s a general overview:

Remove Lock Cylinder

1. Remove the lock from the door.
2. Locate the retainer ring or clip.
3. Remove the retainer to access the cylinder.

Disassemble Lock

1. Insert the current key and turn it to align the pins.
2. Use the plug follower tool to push out the cylinder plug.
3. Carefully remove the old pins and springs.

Replace Pins

1. Insert the new key into the plug.
2. Use the key gauge to determine the correct pin sizes.
3. Place new bottom pins into the plug chambers.
4. Add new springs on top of each pin.

Reassemble Lock

1. Carefully reinsert the plug into the cylinder.
2. Replace the retainer ring or clip.
3. Test the lock with the new key.

Remember, this is a simplified overview. The exact process may vary depending on your lock type and brand.

Different Types of Locks and Rekeying Methods

Not all locks are created equal, and different types of locks require different rekeying methods. Understanding these variations can help you approach the rekeying process with more confidence.

Disc Tumbler Locks

Disc tumbler locks are commonly used in padlocks and specialized door locks. They use a series of slotted rotating discs instead of pins. Rekeying these locks can be more complex and may require specialized tools.

Pin Tumbler Locks

Pin tumbler locks are the most common type found in residential settings. They use a series of pins of different lengths to prevent the lock from opening without the correct key. Rekeying these locks involves changing the pins to match a new key’s cut.

Wafer Tumbler Locks

Wafer tumbler locks are often found in older homes and some automotive features. Instead of pins, they use flat wafers. The rekeying process is similar to pin tumbler locks, but replaces wafers instead of pins.

Common Challenges When Rekeying a Lock

While rekeying a lock can be a straightforward process, there are some common challenges you might encounter:

• Damaging springs or other small components
• Difficulty removing the cylinder plug
• Incorrect measurement of new pins
• Misaligning pins during reassembly

If you encounter these issues, it’s often best to hire a professional locksmith to avoid damaging the lock.

Professional Lock Rekeying Services

Professional services are readily available for those who prefer not to tackle the rekeying process themselves. Let’s explore the benefits and costs associated with hiring a professional.

Benefits of Hiring a Professional

Professional locksmiths offer several advantages:

• Ability to recognize and address unforeseen issues
• Expertise in a wide variety of lock types
• Guaranteed results (which may include a warranty)
• Quick and efficient service

Hiring a professional will save you substantial time if you’re planning to rekey multiple locks.

Costs of Professional Rekeying

The cost of professional rekeying services can vary depending on the amount and type of locks plus your location. Generally, you can expect to pay $50–$100 for professional rekeying services. While it’s more expensive than do-it-yourself (DIY) rekeying, it’s often much faster and yields a high-quality result.

DIY Lock Rekeying Pros and Cons

Deciding between DIY rekeying and hiring a professional depends on your skills, time, and budget. While you’ll increase your home improvement skills, a pro can do a larger volume of locks in less time. Here are some other pros and cons of DIY rekeying:

DIY Pros:

• Builds DIY experience
• Is cost-effective
• Can be done in your own time

DIY Cons:

• Has the potential to damage the lock
• Poses a security risk if done incorrectly
• Is time-consuming

Maintaining Your Newly Rekeyed Lock

After rekeying your lock, proper maintenance is crucial to ensure its longevity and continued security. Here are some tips:

• Apply a silicone-based lubricant annually.
• Avoid using oil-based products, which can attract dirt.
• Check for loose screws or other signs of wear periodically.
• Regularly clean the lock with a dry cloth.

TOH experts also recommend performing these checks at the start of summer and winter since the temperature changes cause the metal components in a lock to expand and contract, which may cause seizing.

Rekeying Multiple Locks To Match an Existing Key

If you want to rekey a lock to match an existing key, the process is similar to standard rekeying but requires careful pin selection. You’ll need to take the existing key to a locksmith to determine the correct pin sizes. This process allows you to have one key that opens multiple locks, which can be convenient for homeowners.

Pro Tip: When purchasing a new lock, Silva recommends selecting locks that have the same code number, as this allows you to use the same key for multiple locks.

Security Considerations After Rekeying a Lock

After rekeying your locks, it’s important to check your home’s overall security with the following steps:

• Be mindful of who you give spare keys to.
• Consider adding additional security measures, such as deadbolts.
• Consider a master key system for controlled access.
• Ensure all entry points are secured.

Where To Get Locks Rekeyed: Hardware Stores and Locksmiths

Many hardware stores offer lock rekeying services. Let’s explore the different options for getting your locks rekeyed and the benefits of each.

Hardware Stores

Hardware stores rekey locks at most locations. This can be convenient if you’re already purchasing home improvement supplies. Typically, you must bring the lock or the key cylinder to the store.

Hardware stores also often have rekeying kits available if you want to attempt the process yourself. The staff can offer advice and support for DIY rekeying projects. However, the range of lock types they can work with might be limited compared to professional locksmith services.

Locksmiths

A professional locksmith might be a better choice for more complex locks, or if you prefer personalized service. Locksmiths can often provide on-site services and handle a wider range of lock types. They have the expertise to address any unexpected issues that may arise during the rekeying process.

Additionally, locksmiths can give you tailored security advice for your specific situation. While professional locksmiths might be more expensive than hardware stores, their services come with the assurance of professional handling and reliability.

Our Conclusion

Rekeying a lock is a valuable skill, offering a cost-effective way to update your home’s security. While you can rekey a lock yourself, it requires careful attention to detail and the right tools. Professional services are a reliable alternative for those uncomfortable with the process, or for those dealing with multiple complex locks. Either way, regular maintenance and periodic rekeying or replacement can go a long way in keeping your house safe.