Have you ever re-keyed a lock? How difficult is it?

I had new exterior doors installed front & back, but they have different keys. I’d like them to be the same. A locksmith can do it, it’s not expensive. However, there are re-keying kits available and I thought it might be a good DIY thing. Is it?

Where would it fall on a scale of 1-10? (1=changing a light bulb, 10=rebuilding a carburetor*)

*I’m assuming this will not be more complicated than rebuilding a carburetor…

About a 5. The hard part is getting the lock apart, but if you have a bit of mechanical intuition, you should be okay.

I cut the pins down on a lock as a kid to see if I could do it. I was successful but it’s not easily done that way. If you can match the pins with a kit it should be pretty easy particularly if the pins are color coded. Match one and you have the layout for the rest of them.

It’s simply a matter of removing the plate that holds the springs and pins in and then pulling the barrel out dropping pins down the holes until flush with the outer diameter (with the key inserted). If the kit has a measuring device that would greatly speed things up. Here’s a diagram to visualize what’s going on.

easier than a carburetor rebuild and a fun project. Most of your time will be spent taking the lock apart as they’re all different. Of course, you have to have matching lock mechanisms to match up your keys.

Instead of doing it yourself or hiring a locksmith, you might want to try a local hardware store. An Ace or True Value or independent store, not one of the big boxes. I had a lock re-keyed at my neighborhood hardware store, and it only cost a couple of bucks. I watched how he did it and I’m certain I could do it myself. But he has this little kit with all the tools and pins and was certainly faster than I would have been.

I did have to remove the doorknob from the door and take it to the hardware store, but the guy there took the lock out of the knob and replaced it when he was done.

Another option is buying a matched set of locks/deadbolts and swapping them out into your new doors. A job on the your scale of about 2.

Local hardware store is who did mine last time. Few bucks apiece.

This is how I usually handle it.
Once, I was installing a deadbolt with a remote keyless option. I didn’t want to change my other keys, so I swapped the cylinder with the old lock. It’s about a 2 or a 3 on the OP’s scale.

I recently had this done at Lowes, and it’s neat to see them do this. I would imagine the popular brand locks may have pin kits that they sell. I bought new deadbolts and they matched my keys to it for free, so that was the way for me to go. They are supposed to charge $5.00, but sometimes they waive it. After watching them, I’d also say it is a 2 or 3 on the easy scale.

Not too difficult. Just keep in mind that you’re dealing with very small pins and springs so a steady hand is a must.

The best way to decide if you want to try it yourself will be to watch a tutorial on YouTube.

Kwikset just to grab one at random.

Then grab a kit from Amazon and go for it.

If the locksets are new, they may support “smart” re-keying. If there’s a small slot next to the keyhole, it’s just a process of inserting the skinny tool in that slot and a specific left-right-left sort of pattern to turn the new key.

Otherwise, re-keying by changing the pins is easy enough, but full of tiny fiddly bits that will want to jump out and escape. Good reading glasses and tweezers may be helpful.

I did something a little different, because I wanted to keep using the same key. I have a door with both a deadbolt and a doorknob key lock, both keyed the same.

The doorknob came irreparably apart. (Broken internal bits, basically.)

I bought another keyed doorknob from the hardware store from the same manufacturer and swapped out the cylinder plug with tumblers intact. (Old doorknob cylinder in new doorknob handler). Worked a doddle. New doorknob is perfectly compatible with old key.

I think the hardest part was making sure the pins didn’t spring away out of the cylinder housing as I freed the plug from the old knob spindle. Pins are little, and the key pins aren’t normally well retained by the plug.

I’d rate that maybe a 6/10 difficulty, but the results were worth it for my specific case.

ETA: I see Digital is the New Analog described the same process as a 2/10. I rated it higher because of the teensy tininess of the pins… because the thing about them springing away wasn’t a hypothetical in my case.

I used to be a locksmith. If you have the right tools, it’s quite simple. But if you fuck it up-- well, you don’t want to fuck it up. There are lots of tiny parts under spring tension and they WILL go flying everywhere (trust me).

If you get a rekeying set at Home Depot or wherever like this, just READ THE INSTRUCTIONS CAREFULLY and follow them exactly.

The crucial step, the one you don’t want to fuck up, is once you get the cylinder separated from the lock, is sliding the follower (the hollow tube) behind the plug into the housing. The housing contains the top pins, under spring tension. The purpose of the follower is to keep everything in place while you’re replacing the bottom pins in the plug.

And make sure the plug turns smoothly in the housing before you put it all completely back together. To check, put the key in and look at top of the plug (the “holes”); the pins should come right up to the top of the holes. They can be slightly over or under and it should still be okay, but any more than maybe 1/2 mm and you did something wrong, and you should start over.

It’s pretty cool to take apart a lock and see how it really works. Diagrams don’t really do it justice. It’s such a simple thing and yet a total mystery to most people. Rekeying was one of my favorite things about locksmithing.