How to Rekey or Change a Deadbolt lock

Click images for a larger version

Deadbolt lock security varies greatly due to age, manufacturer and quality of the lock. All deadbolt locks should have a 1" long bolt that, when fully extended, locks (dead bolts) in place. Prying on the bolt should have no effect if the bolt is well designed and installed properly.

What you can do - Remove the lock from the door and take it to a lock shop to have the cylinder(s) rekeyed. Caution: If you try to replace your lock with a new style lock, the holes in your door and frame may not be the same sizes.

If you can see 2 standard screws on the inside plate (as shown in the second image above), you have a simple design. Remove the screws and remove the lock slowly. Don't drop any parts. If you have one-way security screws (as shown in the third image above) you can usually loosen them by tapping the head of the screw around counter clockwise with an old chisel and hammer. Then use a pliers to finish taking out the screws.

If you do not see screws on the inside plate, your lock may have hidden screws. Some lock manufacturers who have hidden their screws are Medeco, Arrow, Schlage, and Lori.

Arrow double cylinder deadbolts (keyed on both sides) require you to insert the key in the inside key cylinder. Turn about 1/4 turn to open the access holes to the screws. Use a thin phillips screw driver to go in the holes and remove the screws.

Medeco locks have a cover plate over the screws. There is a thin wire in a groove in the inside plate. If a single cylinder, loosen the set screw in the under-side of the thumbturn with a very small allen wrench. Remove the thumbturn. Find the end of the wire and remove the wire from the groove with a tip of a knife (or something with a point). The brass plate should come off. Now you can see the screws to remove the lock.

Lori locks are similar to mortise locks. The outside cylinder and possibly the inside cylinder screw into a housing. You will find the set screws by removing the face plate of the bolt on the edge of the door. There is an opening on each side of the bolt. You should need a 5/64" long allen wrench to reach and loosen the set screws. Then unscrew each cylinder.

Schlage older double cylinder deadbolts may have brass caps driven into the heads of the screws. Take a small chisel and tap around the line of separation between the cap and the screw. It should loosen up and pop off. If not, you may have to drill the screws off. The B600 double cylinder requires you to pry off the inside face plate carefully in order to re-use it.  The first image is of the screw and cap apart.  The second image is of the cap in the screw head.

What a locksmith can do - An experienced locksmith will have the tools to remove the locks and re-pin (rekey) the cylinders in your house or in his truck and then reinstall them.

Since deadbolts are the serious security on your doors, he should advise you of any weakness to your door or frame. If your lock is older or of poor quality, he may recommend a better lock.

How to Rekey or Change a Rim or Surface Mount Lock

These locks are usually mounted above the door knob lock. They might be called night latches, rim bolts, slam locks, jimmyproof locks or surface mount locks.

They usually have a key cylinder on the outside of the door and a large body on the inside of the door that will lock or latch into a surface strike mounted on the door frame.

What you can do - Remove the lock and have the cylinder rekeyed or replaced.

You must remove the inside lock body. It will be held by screws that might be standard screws or one-way security screws. One-way screws can be hard to remove. If you have a dremel tool(trademark) you can cut a slot in the head of the screw. Or you can use an old chisel to tap on the edge of the screw to drive it counter clockwise until you back it out enough to grab it with a pliers and remove it.

If you don't see any screws, they may be hidden. There may be a plate that has to turn or come off. You may have to turn the key to remove the plate.

When you have removed the lock body, you will see the plate and screws that are holding the outside cylinder to the door.

Remove the cylinder and take it to a lock shop for an exact replacement or have it rekeyed. If your lock uses a key on the inside, take that part to be changed too. Bring a working key, if you have one.

Finally, if you buy a replacement cylinder, you will probably have to cut the tail-piece and cut the screws to the correct length. Then reinstall. Some locks have a shutter that may be blocking the tail-piece from going back in. Locate the spring and gently press on the spring while pushing the lever to open the shutter.

What a locksmith can do - Rekey your lock and possibly match your other house key so you have less keys to carry.

These locks are probably the easiest for a do-it-yourselfer to install. That is probably why they can be a bear to reinstall. The original installation, if not done correctly, can make it difficult to get things to line up and work easily when you reinstall.

An experienced locksmith may have to shim here and there or re-drill the holes before he can reinstall the lock he took off and rekeyed.

How to Rekey or Change a Mortise Lock

A mortise lock has a cylinder that screws into the lock body. This cylinder can be removed and rekeyed or replaced so your lock will work with a different key. (Click above images to see larger version)

What you can do - Remove the cylinder and take it to a lock shop for a replacement or re-pinning.

First you must loosen the set screw. Look at the edge of the door. You may have to remove a face plate to see the set screw(s). There should be either 1 or 2 screws just above the bolt, in line with the center of the cylinder. If you have 2, the screw closest to the outside of the door is the one holding the cylinder.

If you have the single screw type, the screw may turn clockwise or counter-clockwise. As you turn, the screw will move out toward you. CAUTION: Do not force or try to remove the screw - This will ruin your lock!

If you have the two screw type, loosen the screw about 4 turns. CAUTION: Do not remove the screw. It is hard to get back in and may fall inside your lock body.

When your set screw has been loosened, grip the cylinder and try to unscrew it from the lock. Or you can put the key 1/2 way in to use as a handle to turn the cylinder. CAUTION: Do not force the cylinder to turn. You may break the lock case and ruin your lock!

If you have been successful, the cylinder is now out of the lock. Take it to a lock shop to either get an exact replacement or have the internal pins replaced so the lock will work with a different key.

Then with the door open, reinstall. Carefully line up the cylinder so it threads in EASILY. Do not cross thread. When the cylinder is in and straight, tighten the set screw until snug, not too tight. Check the operation of the lock several times. If all works well, close the door and again check the operation of the lock and your new key.

What a locksmith can do - Many of these locks are around 100 years old and can give you some surprises. You may have a lock that is already broken. It may have the wrong parts. The cylinder may be "frozen" in place from years of not being removed.

An experienced locksmith will be able to service your lock or offer options if a lock is not serviceable for any reason. Replacement mortise locks are still available. They are a close fit, but some work is needed to try to cover all the holes and scarring of the current lock. Marks, Emtek and Baldwin companies make mortise locks.