How to Change Your Lock Cylinder

If all you need to do is change the key to your lock, and you are fairly good with tools, you may want to do it yourself. Or, you may want to remove the lock and bring it to a locksmith to be rekeyed. In rekeying, only tiny parts within the cylinder are changed; the rest of the lock stays the same.

Following is an overview of the various locks there are and how to change them.


In order to change your lock, you can replace your entire lock, or you can replace just the cylinder, or you can take just the cylinder to a locksmith to be rekeyed. There are three basic types of cylinders:

  • Rim cylinders
  • Mortise cylinders
  • Cylindrical lock or tubular deadbolt cylinders

They are each pictured below:

Rim Cylinder

Sargent Rim Cylinder
Sargent Rim Cylinder

Mortise Cylinder

Sargent Mortise Cylinder
Sargent Mortise Cylinder

Cylindrical Lock Cylinder

Sargent Cylindrical Lock Cylinder
Sargent Cylindrical Lock Cylinder
Corbin Russwin 4200 Series Cylindrical Lock
Corbin Russwin 4200 Series Cylindrical Lock
Arrow Latch Face with Brand Name
Arrow Latch Face with Brand Name

Cylindrical Locks

Cylindrical locks are one of the most common types of locks, but can be deceptively complicated to change. If this is the only lock on your apartment door, or if you want actual security, you might consider just leaving it alone and installing a deadbolt above it, since a cylindrical lock provides basically very little resistance to burglary.

Because of the great differences between cylindrical lock cylinders of different manufacturers and even between different product lines of the same manufacturer, it may not be feasible to purchase a replacement cylinder in advance unless you know the exact make and model of the lock. If you do not have a replacement cylinder in advance, you will have to leave the secured space open while you fetch a new cylinder or get the existing one rekeyed, so plan to have someone watch the space while you are gone.

Many manufacturers offer their cylindrical lock installation instructions online. If you identify your cylindrical lock make and model you may be able to find these instructions online.

Above right is shown a cylindrical key-in-knob lock. Below that is the latch face of a cylindrical lock, where you can usually find the brand name. Below this section is an illustration of a cylindrical key-in-lever lock.

To access the cylinder, you will need to remove the outside knob or lever. To do this, you will need a piece of stiff wire and the key to the lock. In the illustration below I have (rather crudely) indicated the location of the all-important poke hole. If you determine that your lock has no poke hole, that means that your lock is either cheap, old, or complicated to disassemble. Your best bet is to replace the whole lock.

If your lock indeed has a poke hole, to remove the outside knob or lever, insert the key and turn it 90 degrees. Depending on the lock function, this action may or may not retract the latch. With the key turned to 90 degrees, insert a piece of stiff wire or other slender, rigid object straight into the poke hole. Beneath the poke hole there is a pin which must be depressed in order to allow the lever or knob to slide off. This process would be easy if you had three hands. To remove the knob or lever, you must pull on the knob or lever while depressing the pin beneath the poke hole and turning the key to the 90 degree position. It should slide off with a small amount of force.

Once you have removed the knob or lever, look inside from the back. The cylinder should be loose inside the knob or lever, or held in by a piece of plastic or sheet metal. Remove whatever is holding it in and remove the cylinder. Now look on the latch face (visible on the edge of the door) for the brand name of the lock. Armed with the brand name of the lock and the cylinder, you should be able to bring the cylinder to a locksmith and either purchase a replacement cylinder or have the locksmith rekey the cylinder as an over the counter transaction.

Illustrated Cylindrical Lock

Sargent Tubular Deadbolt
Sargent Tubular Deadbolt

Tubular Deadbolts

To avoid confusion, try to find installation instructions for your brand of deadbolt online. Like cylindrical locks, deadbolts often have their brand name stamped on the latch (or bolt) face (see picture of Arrow Latch Face above).

While tubular deadbolt cylinders can often be similar in appearance to cylindrical lock cylinders, they are usually much easier to get to. If the lock has a key on the outside and a thumbturn on the inside, simply unscrew screws until the lock comes off the door.

If the lock has a key inside and outside, the screws that hold the inside cylinder on are probably concealed. The usual way they are concealed is with drive-in covers, that is, screw covers that are tapped into place with a hammer. These screw covers are sometimes difficult to remove without damaging them. Some double keyed deadbolts have a shutter that turns when the inside key is turned. When you turn the key to a certain degree, holes appear which allow the lock to be removed. Once the lock is removed, the cylinder will be clearly visible.

The outside cylinder will be held into the outside housing with a clip or screw, or it will actually be the outside housing.

As with the cylindrical lock, you can usually look on the edge of the door where the bolt projects and find the brand name of the lock. Armed with the brand name of the lock and the cylinder in hand, you can take your cylinder to a locksmith for rekeying or replacement.

When you are at the locksmith shop, ask if it would be cheaper to rekey the lock or to replace the entire lock with an equal lock. The locksmith will probably express an opinion about the quality of the lock. Based on that opinion, you can decide whether you might want to upgrade to a better lock.

When you reassemble the lock, note that the tailpiece, that is, the piece of metal that connects the cylinder(s) to the bolt, is (are) "timed". That means that they must be rotated so that the tailpiece is free to turn when the bolt is thrown by the turnknob or other cylinder. Such tailpieces are called "lazy" tailpieces because they are passive, allowing themselves to be turned by an outside force. You will know that you did it wrong if you reassemble the lock and then find that you cannot lock or unlock it from one side or the other.

Mortise Cylinder
Mortise Cylinder
Step 1
Step 1
Step 2
Step 2

Mortise Cylinders

Mortise cylinders are much easier to deal with than cylindrical lock cylinders or tubular deadbolt cylinders, but there are still a couple of things you need to know in order to get one in advance, and those are:

  • Cylinder length (dimension "X" in the illustration above left)
  • Cam style (above right)

The cam pictured above is specific to Sargent mortise locks. Different manufacturers use different cams for different models of mortise locks. If you have the wrong cam, your cylinder will probably not work right.

You can take the mortise cylinder with you to the locksmith shop and tell the counter person that you want one just like it. Of course, while your cylinder is out of the lock, your door is not secure.

A mortise cylinder is actually a big machine screw. It theads into the body of the mortise lock. It is kept from turning by a set screw. To remove the mortise cylinder from a mortise lock:

  1. Remove the lock front, or faceplate, by removing the two faceplate scews as shown above right
  2. Loosen (but do not remove) the cylinder set screw (next picture down)
  3. Turn the mortise cylinder counter-clockwise until it comes out

To put the new mortise cylinder in:

  1. Thread the mortise cylinder clockwise into the lock body
  2. Tighten the cylinder set screw (DO NOT OVERTIGHTEN)
  3. Re-install the mortise lock faceplate

Rim Cylinder Back Plate
Rim Cylinder Back Plate

Rim Cylinders

Rim Cylinders are the easiest of all cylinders to replace. For one thing, since there is very little difference between rim cylinders made by different manufacturers, you can just go buy one and it will probably work just fine.

To remove your old rim cylinder:

  1. Remove the lock from the door
  2. Remove the two screws that hold the rim cylinder in place

To install the new rim cylinder:

  1. Cut the tailpiece if necessary with a bolt cutter or hacksaw
  2. Fasten the rim cylinder screws through the cylinder backplate
  3. Re-install rim lock

Very easy. Cutting the tailpiece can be challenging if you've never done it before. Just be careful not to cut the tailpiece too short.

© 2008 Tom Rubenoff

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Comments 35 comments

shanel profile image

shanel 6 years ago from Seattle

What a wonderfully, detailed hub regarding locks. I have run into trouble trying to reset tumblers a couple of times where I get the springs jammed in the cylindrical lock cylindar. Your directions are really clear and precise. Thanks.

Tom Rubenoff profile image

Tom Rubenoff 6 years ago from United States Author

I am glad that you found my article useful, Shanel, thank you!

scaffolding tower profile image

scaffolding tower 6 years ago from United Kingdom

Very detailed. Now, instead of waiting for the landlord to "come see what's broken" one could read through this and change the lock without much help. Good stuff.

Exit Alarms 6 years ago


Tom Rubenoff

it is very nice article it is also useful for those people who change locks

thank you

Locksmith Melbourne 6 years ago

Excellent article Tom! Thanks

Locksmith Brunswick 6 years ago

Very informative article.. Ty

SD-Locksmith profile image

SD-Locksmith 5 years ago from San Diego

This is so much more than an overview! Wow! For those who happen to be in San Diego and are not so great with tools, we'd be happy to help - and at a discounted rate if you mention Tom's hub.

Buffalo Locksmith 5 years ago

Great article!!

Tom Rubenoff profile image

Tom Rubenoff 5 years ago from United States Author

Thank you, locksmiths!!! :D

Locksmith Toronto 5 years ago

very well written, Clear and simple

Tom Rubenoff profile image

Tom Rubenoff 5 years ago from United States Author

Thank you!

Tom Rubenoff profile image

Tom Rubenoff 5 years ago from United States Author

I appreciate that locksmiths are drawn here, as I am one.

locksmith 5 years ago

Q- Why is it necessary to re-key your locks? -

A- It is necessary to re-key your doors for many reasons. If you have just moved to a new home, the previous home owners could have duplicated the key and have full access to enter your home and steal from you. Another reason is after a certain amount of time the pins and bolts are not as strong leading to easier break In’s. Another big reason is money; everyone wants to save money so re-keying saves you money.

Q- Are Jimmy Proof products a good idea to put it? -

A- Jimmy Proofs are very good. These are much more complex than doorknobs and dead bolts. Jimmy proof locks are created differently; two vertical bars are interlocked when you turn the knob to secure the jimmy proof. This causes the door to be extremely strong because there is no room between the door pry bar and the jamb.

Q- Why is it that Dead Bolts are better than doorknobs? -

A- Dead Bolts are better than regular doorknobs for many reasons. Doorknobs are easily picked. For example, you can slide a credit card or an ID and easily unlock a doorknob. On the other hand, a dead bolt lock cannot be easily picked. When you secure the door the lock goes way further into the door causing it to be secured better. An ID cannot push open the lock it would take a lot more than that!

Q- Are Biometrical ways of security worth using? -

A- Yes, Biometrical wats of security are worth using if you have the money. Most biometrical ways of security are used in buildings like hospitals, schools etc. Not a lot of people use Biometrical security in there homes because of the price. Biometrical Lock- Locks that can only be opened by a fingerprint (the owners fingerprint)

Q- How can you tell when your doors need re-keying?

A- it is best to re-key your doors every 5 years because 5 years is a long time. someone could have copied your key and etc. Another time is after a break in, if you have experienced a break in you should change the cylinders because they have been damaged.

Q- What's the difference between a panic bar and a push bar?

A- panic bar is the same thing as a push bar. the purpose of the panic bar is in its name. if there is an emergency thee easiest way to run out of a building is tosh the door open not turn a knob. All schools and hospitals must have panic bars. these bars are on the inside of the building not the outside.

Q- How to Re-Key?-

A- 1. Check the brand on every door; your locks might have different manufactures. Purchase a re-key kit for every brand you have. They are easily accessible at home stores and online. The kits come with two keys and tools to re-key six door locks.

2. Unlock the door, and remove the doorknob by inserting the wire tool, which you will find in your kit, into the hole on the knob. Release the clip and take of the knob.

3. Push the lock cylinder out of the knob. Once the knob sleeve drops off, use the retainer ring tool, also in your re-key kit, to free the cylinder.

4. Using your old key, turn it ninety degrees left or ninety degrees to the right. Take the key out and push the plug through with the plug follower tool in your kit. put even pressure on the plug and tool to make sure you don’t lose your springs by accident.

5. Empty the plug pins and put the new key in the product. Use tweezers or forceps to insert the new color-coded pins into the plug. Follow the kit instructions to ensure the new pins are put in correctly. Reassemble the doorknob after all this is done.

Milwaukee Locksmith 5 years ago

Locksmiths Milwaukee provides 24 hour residential Locksmith solutions for homes and commercial Locksmith services for businesses in Milwaukee. We also provide auto locksmith services for car lockout emergencies. All of Locksmiths of Milwaukee security expert technicians are licensed, bonded & insured. We not only guarantee professional service, but the quickest & best solutions to your security needs as well.

John 4 years ago

What if the mechanism inside the Cylindrical lock where the key fits in all came off . It's practically in pieces now . How do i re-assemble it ?

Tom Rubenoff profile image

Tom Rubenoff 4 years ago from United States Author

Hi John. I will write a separate article on disassembling and reassembling a common pin tumbler cylinder down to its most basic parts, but in the mean time it may be simpler for you to buy a new cylinder instead. Also, how did it come apart? If it came apart spontaneously, in may need replacing anyway.

ian groves 4 years ago

hello can any one help i have a 3 lever i think the type that you pull handle up before you lock door,im after changing just for new keys is this possible.

Tom Rubenoff profile image

Tom Rubenoff 4 years ago from United States Author

Not sure what you mean by 3 lever. Is there a brand name on it? Does the cylinder look like any of those above?

Tom Rubenoff profile image

Tom Rubenoff 4 years ago from United States Author

Thank you!

Debby Bruck profile image

Debby Bruck 4 years ago

Wow! Tom you are like the hub of locksmiths. They all clamber to unlock the door with their identity skeleton key. And leave some cookies and milk on the table. Blessings, Debby

Tom Rubenoff profile image

Tom Rubenoff 4 years ago from United States Author

Yes, Debbie, well, at least cookies. They love it here. They are my brother and sister locksmiths and of course they are welcome.

Juanita 4 years ago

I need help to remove a jammed jimmy proof deadbolt (vertical bolts). I am locked out so I cannot access the interior side of the lock. I don't mind damaging the lock in order to unlock the door.

Tom Rubenoff profile image

Tom Rubenoff 4 years ago from United States Author

I'm sorry, Juanita, but that is something I will not discuss online. I wish you good luck. I think it is best to call a locksmith because they will be able to get in with the least amount of damage to your door.

tony 3 years ago

I have a cylinder lock with a keyhole on both faces and was only left with one key by the previous householder. unfortunately that key broke in the lock and I can't get the cylinder out to replace it. I have dismantled another similar lock to investigate the issue and in the middle of the shaft there is a latch that protrudes to lock the barrel in place when the key is centred (as it is on the lock with the broken key). Can you advise me if there is any way I can overcome this latch to allow me to replacee the cylinder

Tom Rubenoff profile image

Tom Rubenoff 3 years ago from United States Author

It sounds like you have a double keyed cylindrical door knob or lever lock and the handle can only be removed when the key is turned 90 degrees. Therefore the only ways to overcome the problem are to either remove the broken key and duplicate it or destroy both cylinders so that the lock can be removed and the cylinders replace. Of these two, to first option would be by far the easier.

Micahwilson profile image

Micahwilson 2 years ago

It's important to have the right tools if installing a new deadbolt so the job goes quickly and no mistakes happen. If you live in the San Diego area you can contact for fast and personal service. We are available 24/7 to help with your home security needs.

Tom Rubenoff profile image

Tom Rubenoff 2 years ago from United States Author

Thanks for that tip, Micah.

Raffy 2 years ago

Tom: I am trying to figure something out. My locksmith told me that in order to replace a Baldwin 5024 knob cylinder (that I will order, but haven't yet) with a GMS cylinder, I need to find out if it "is the same cylinder which fits into A cylinder knobs". The guy at Baldwin was out for the day that knows about cylinders, and this is not about the keyway. I can't even find anything online about A cylinders, except locksmith did tell me that it is medium duty (not heavy duty). I can't order the knobs until I have this piece of information. Do you know if this is the case? I've looked at Baldin website and done Google searches, but nothing mentins what type of cylinder comes inside the knob.

Raffy 2 years ago

And more - I think he said the knob would need to have a "screw-on tailpiece that's flat. Not stubby". How would I find this out? Have looked at Baldwin website, but will look again.

Raffy 2 years ago

Sorry, it's the 5025 Baldwin knob.

Tom Rubenoff profile image

Tom Rubenoff 2 years ago from United States Author

I am not acquainted with GMS cylinders, but I should be able to identify what the tailpiece arrangement is by looking at Medeco replacement cylinders for the Baldwin 5025. I will let you know what I find out.

Team Wiseman profile image

Team Wiseman 21 months ago

Perfect! This article is exactly what one needs. Well written and detailed PLUS was super easy to understand. Thumbs up , Useful + followed you on all social sites. Also gonna Share this article with FB, Twitter, g+, and Pinterest for anyone who may need this info. Oh yeah, Bookmarked you also. Thanks for the well written advice!!

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Tom Rubenoff 21 months ago from United States Author

Thank you, Team Wiseman!

Peter 4 months ago

Thank you I am in Almeria Spain with a broken door lock, your very detailed information has enabled to repair my front door lock and secure my property once again. Thank You.

Tom Rubenoff profile image

Tom Rubenoff 4 months ago from United States Author

It is wonderful to know when my writing helps someone! Thanks for letting me know. Thank you.

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