How to Change a Lock





Introduction: How to Change a Lock

About: My name is Randy and I am a Community Manager in these here parts. In a previous life I had founded and run the Instructables Design Studio (RIP) @ Autodesk's Pier 9 Technology Center. I'm also the author ...

Changing the locks is a quick, cheap and easy way to get peace of mind about your living situation. It requires little technical skill and no tools fancier than a screwdriver to replace the common deadbolt. Over the course of these instructions I will teach you how to replace a basic dead bolt lock. This is an extremely handy thing to know how to do.

While we often don't think we will need to change the locks, things do happen. Roommates are known to go crazy, lovers are known to have a change of heart, and keys are known to get stolen. By simply changing the deadbolts on all of the entryways to your home, you can ensure no one can easily unlock the door and walk in. If you are at all worried about your safety or well-being, there is no reason not to do this. After all, a new lock can be purchased for as little as $15 at your local hardware store and installed in under 10 minutes.

Step 1: Purchase a New Lock

Go to the store and purchase a new lock. You will want to find one that is keyed on only one side and has a turn assembly on the other.

The locks tend to be rated for their effectiveness, and it often does not cost remarkably more for one that offers higher security. Find the one that you are most comfortable with that is within your budget.

Most basic dead bolt kits include:

- A key lock cylinder
- A deadbolt assembly
- An interior turn assembly
- A steel strike plate (typically not necessary)
- Mounting hardware

Step 2: Remove the Old Lock

Remove the two visible bolts in the turn assembly plate and then remove the turn plate assembly itself.

Finally, pull free the deadbolt lock assembly.

You should now be able to see through the hole in the door.

Step 3: Remove the Old Deadbolt

Look at the deadbolt plate on the side of the door and locate the two screw heads holding it in place.

Remove the two screws and then simply pull the dead bolt out of the door.

Step 4: Insert a New Deadbolt

Basically, you are going to now do everything in reverse. However, when installing the new deadbolt you need to be mindful of the orientation of the different parts.

It is very important to install the new deadbolt facing "up." Fortunately, most new deadbolts are labeled with the word "up" on the side which is supposed to be facing up. This makes life easy.

If on the off-chance it is not labeled, you can orient the deadbolt by matching the components to the picture shown above.

Once oriented, insert the deadbolt into the door facing up and use the short woodscrews to firmly fasten it in place.

Step 5: Insert a New Deadbolt Lock

Insert the bar protruding from the new deadbolt lock through the channel in the deadbolt itself. Position the lock mechanism such that the keyhole is vertically aligned.

On the opposite side, insert the bar into the channel in the back of the turn assembly plate. Orient the turn assembly plate such that its top side is at the top.

Twist the knob on the turn assembly to expose the bolt holes. Use the included bolts to fasten the key assembly and the turn assembly firmly together.

Step 6: Test the New Lock

Once the new lock is firmly fastened in place, with the door still open, test it out using both the interior turn assembly and the key lock.

Once you are sure it is working, test both with the door closed.

Assuming that they are both still working, you have changed the lock. Congratulations. Be Safe.



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    You can also buy locksets that can be re-keyed without having to remove anything from the lock. Kwikset calls their locksets of this type "SmartKey" and I've used them on my home and on rental properties for several years without a single problem. So long as you have a single copy of the current key you can re-key a lockset in a few seconds.

    1 reply

    Yes, Schlage makes these too. I"m not real fond of them because it's easy to screw up changing them. If you think about it, changing the comb on your locks isn't something you need to do very often. You can simply take the lock to a a hardware store or locksmith and have the lock changed to new keys for not too much money. Alternatively, you can keep a spare lock to swap out.

    I really liked this step by step, it's really helpful, and the pictures are great. My husband and I recently had to change the locks to our home after I lost my keys in a grocery store. It seemed like a really complicated process, but your explanation made things a lot easier! Is there a specific brand of locks that you prefer to increase home security?

    Be cautious of doing this in your apartment or rental home. It generally frowns upon it in the lease.

    Please don't use this to teach otherwise idiotic people how to open my door.

    I am a locksmith with 35 years experience. Having the combination changed is more affordable. If you have a window in or next to the door, a lock with key cylinders on both sides is preferable (as long as local codes allow and you keep a key within reach). I don't recommend the "you change it" locks-too many ways to screw them up. Be aware the weak point for attack is generally the door frame, so a reinforced strike plate with longer, heavier screws is needed. Better locks come with these. Having all locks keyed alike is not only more convenient but safer. Don't bother with cheap locks, they're too easy to defeat.

    4 replies

    I learned of another safety issue with just replacing the locks yourself. I purchased 2 packages of locks...with regular and deadbolts in the the local 'depot'. After I installed them, I realized the keys for one package fit ALL of the locks, not just for the one package. I called the company and learned that ALL the locks packaged into one case can have the same key! If someone was aware of this when I was shopping, they could have bought a set right behind me, followed me home and had access to my house!

    That may be, but don't let paranoia cripple you too much. That "person who may follow you" would have to know the codes to the packages you have because knobs and deadbolts are constantly being sold and items are condensed to make the shelves look nicer. Most of the times employees don't even know this little fact even when they work in that department. Nothing to sweat over.

    Personally I 100% agree with your advice to use a double cylinder lockset on any door that's located near a window of some sort, but nowadays just about every city/town/etc. calls for single cylinder locks on all exterior doors due to fire safety considerations. Some insurers won't insure a property if it has double cylinder locksets on any opening that is intended to serve as an emergency exit.

    As I've heard the fire marshal explain it, when everything is said and done, you don't want someone dying in a fire or other emergency because they just couldn't figure out where the key was located. It's painfully easy for people to become disoriented in a fire and while you might know exactly where the key for a door is, a child, guest, repairman, etc. might not and even if they did, they could get disoriented during an emergency and not be able to walk a few steps to get a key and successfully operate the lockset.

    I am also a locksmith (28 years) and completely agree with your advice.

    Ultimately all locks are unsafe to some degree:

    I find it interesting that a locksmith would be talking about how easy it is to defeat a SmartKey deadbolt with a "simple tool" when you can do something similar with a bump key on a large number of locksets out on the market. It seems a little self-serving since I'm sure he makes some $$ re-keying locks but he doesn't seem to be advising people against using all normal deadbolts that are susceptible to being bumped.

    Two small details that I've learned the hard way.

    a) Measure the door to make sure that the lockset you buy is the correct size. Door thickness can vary as can the exact location of the hole for the deadbolt relative to the edge of the door. They'll usually be standardized, but on old doors they may not be.

    b) Depending on the handedness of your door you may need to rotate the bar that goes into the deadbolt so that it can throw the deadbolt when you turn the thumb latch or the key. You'll want to make sure that the bar is rotated (clockwise or counter-clockwise) so that the top of the bar is rotated towards the middle of the door. This way turning the thumb latch or the key towards the edge of the door will lock it and turning it in the opposite direction will unlock it.

    Another option if you have concerns of lost keys, disgruntled roommates, etc. is to take the key lock cylinder to your
    nearest big box hardware store and get it re-keyed. I have done this a couple of times. It only
    takes a few minutes and it costs $5.00.

    2 replies

    i bought one new for $60, then paid my neighbor $20 to put it in for me. i'm doing the $5 method from now on! thank-you, peinkc!!

    I just got an electronic lock its just a matter of changing the codes and they are really not that much more expensive anymore

    GREAT ADVICE from EVERYONE ~ THANX, you guys!!

    You can usually buy "keyed alike" deadbolts and locksets (Door knobs and their mechanisms) that use the same key. This way one key works for front, back, side and even outbuilding or garage doors.