1. Type of key?
The brand is Phillips but they make various types. The type here is (not sure of the correct jargon) without vertical ridges and notches. And both sides of the key are identical.
I've looked at some diagrams of key types and I'm not sure exactly. Is it a "dimple key"? Something else?
2. How to remove broken part from lock?
Location: Door between bedroom and garden.
Situation:
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Someone bent the key a little, and it was stuck, couldn't get it out. On the inside of the door. At that point still able to lock and unlock from the inside only. Using other key from the outside does nothing, doesn't even turn.
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I tried gently straightening it but it immediately snapped.
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Now: can still open and close the door using the handle. Can still, with difficulty, lock and unlock the door (from inside only) by carefully pressing the head of the key against what is in the lock and turning.
A lot of info online for removing broken key blades from locks are for the "traditional" kind of key with vertical ridges and notches.
I have a screwdriver that fits all the screws and I can access all sides of the lock (inside, outside, edge), but I'm not sure if that's relevant. I've tried tweezers but it's too snug.
If I need more tools or equipment, I'll get them tomorrow.
Unlock the door and remove those screws holding the latch in the door.
Once you’ve removed the lock you should be able to disassemble it and push the stuck key out or worst case, replace the lock cylinder.
This is the answer.
The only downside is you can see how stripped those screws are even in this photo. That'll be fun.
On this type of latch (mortise) the third screw is often stripped (because it’s a set screw that holds the lock cylinder in place and often the notch in the cylinder is misaligned / on the wrong side) but _un_screwing it should be easy.
The cylinder itself, however, is usually finely threaded and can require a fair amount of torque to get started, especially without using the key for additional purchase.
Yep. Use a rubber band in the screw when trying to unscrew it to help with a bit extra grip and then never use those screws again either. Either that or use a Dremel to turn it into a flat head screw and remove them.