It’s my understanding that mass produced items are all basically the same. If you buy something like a toothbrush, for example, then any other toothbrush from that same assembly line is going to be basically the same and have all the same specs (with the exception with minor defects here and there), because the machinery and process to make any those toothbrushes are all basically the same.
But that can’t be the case with locks and keys. Because if every lock and key were the same then there’d be no point in having them. Anyone could just bought the same key/lock combo could use it to unlock your front door. So all or most keys and locks must be unique. So how are they mass produced in a way that preserves their uniqueness?


Actually, a lot of locks ARE the same. I lived in a brand-new complex years back, and everyone had the same lock and key. It didn’t take long for some kids to start breaking into other people’s houses, and since it was all under HOA owners couldn’t just buy mismatched locks.
Then when I bought a 10 yr old home later, I was sitting at the house when some maintenance crew unlocked my door and walked right in. They tried to tell me I was squatting and it wasn’t until they realized they were to do work on my neighbors house. Went and checked with other neighbors and found out a handful of us all had the same keys of about 4 varieties. Ironically, there were even two families that knew this before then and they told us how they bought new locks - and found out that those too were the same key.
So basically, if you buy a new lock, you should have it checked by a locksmith and rekeyed if needed.
Edit: There is a lot of side discussion on this post. Feel free to inquire and discuss, but note that context was left out in a lot of places. I understand HOAs can be difficult, but the OP is about locks. Just be mindful that there is more to the story I did not detail.
When my wife and i moved into a flat, I noticed the lock was nearly done for. So I exchanged the cylinder with something that was a real quality lock, and gave the landlord a copy of the key in a sealed case.
When we moved out, I informed the landlord that we had exchanged the lock because it was busted, and i would replace the current lock anyway - if they provided a new cylinder i would install it for them. They declined and insisted that I install the original lock. They didn’t test it, and had to get a locksmith…
Weird they didn’t just rekey the cylinder instead of a whole new lock and setup.
I don’t know the outcome, I left shortly after. People owned these units, HOA can force a particular style of lock to match all the other units, but they can’t bust into homes and force homeowners to change their locks. How each homeowner resolved the issue wasn’t their concern, but I do think they hired a locksmith as a courtesy. It just took HOA a long time to figure out what to do.
I’m in an HOA, I know their bullshit.
Its a condo, so not a lot we can do outside our door. BUT, I put a custom doormat, after going through the rules and seeing nothing about that, at all. Got a notice I had to change it, said “please show me where in the rules, it specifically states it’s the only thing I can customize”. Never heard another word about it.
They provided cheap rubber ones, and the rules said if we lost it we could get another for $25. It never said anything about trashing that one and putting my own.
Got a door cam because the unit across kept leaving trash in the hall. Found out owner was renting it as an Airbnb, so when they complained about my camera I replied with why I have it. Not another word about it.
I understand there are rules, but there are also legit reasons for certain things that break the rules, case by case. Will not buy into another HOA home
as an european, i always roll my eyes at the concept of hoa, but this is definitely wildest i have seen in this context 😂
Yeah even for HOA standards this seems crazy though. Like, not being allowed to change your lock? That seems like a massive security risk. Especially given the circumstances. Why does the HOA even care do they need access to everyone’s place?
They don’t, they just didn’t want some regular old locks on some doors mixing with their fancy locks they overpaid for that matches all the other units.
I am still confused. Aren’t locks modular and easily swappable on the other side of the ocean?
This is how they look here. You can just swap it without changing the looks of the door in any way.
Your confusion stems from the bureaucracy, not the method. Even if it was ‘simple as’, the result is the same.
Some doors yes, other doors you have to take the whole thing apart. I would say most are not ‘easy’. I don’t know the outcome, I think they were rekeyed because I was told to keep the lock even if I replaced it. I left that week for unrelated reasons and had my property manager deal with it.
I see
Yeah, but they were somewhat reasonable about it. You could get new locks to prevent break-ins, but it took them a very long time to figure out what they were going to do. It was all brand new and the locks technically worked, so I guess they had to have meetings to figure out if they needed to sue or to buy new locks, change the design…or whatever the HOA does. They ended up telling everyone to keep their old locks and I think they just rekeyed them? I left during all that mess (not for that reason) so idk.
Most apartment locks and such are made for the purchaser to be able to easily and quickly re-key. You set it to be rekeyed, put a cut key in, and then lock the key pattern for it in place. Takes like 5 minutes or less. That way every time someone moves out you can keep things secure without replacing the lock.
In your case, the building manager was just a lazy fuck.
It is common for lock makers of normal locks to do production runs of just like 50 different key sets.
There was a building manager (if it could be called as such) but they were responsible for coordinating mandatory inspections (fire hazards, alarms, etc) and common areas. They were absolutely not responsible for keys. Not all places are the same.
Edit: Should also mention people owned these properties, it wasn’t rental apartments.
New locks usually tell you what key set they are on the package… So you can buy multiple of the same lock to rekey an entire house.
While the locks can be rekeyed to thousands of options, the prepackaged options will only be a few sets.
Yeah, and I think when homes are manufactured they just buy sets in bulk. One would think they would rekey them, but I guess not. I mean, even if they were, you should rekey your locks in any new home anyways - but even I fell victim to that because despite knowing this, no one ever does, and it happened twice. You think one would learn.
They won’t bother rekeying, but they normally are buying enough that different sets are inevitable even if they don’t actively try.