doorslockscrewstools
Help! I am trying to replace my lock with a new lock that I bought at bunnings and I’m here with my screwdriver but look at this what kind of screwdriver do I need for this! What is this. I’m very confused. I tried poking it but it doesn’t come off. What can I use to remove the lock??
For a lock that's 50-60 years old, I'd be tempted to replace the whole thing. Just go to the hardware store and pick a similar one up so all you need to do is unscrew the old and screw in the new. Typically the inside of the lock is screwed into the outside half of the lock, and the bolt is screwed into the door on the side.
The biggest gotcha is if the hole changes size or position, not uncommon with an old lock, which is why you're better off finding a very close match. When I had to enlarge a hole in a metal door, I managed to rig two hole saws together on a common center mount so that the smaller hole saw guided the larger saw. Without this particular hole saw model, or if you need to shift the position of the hole, you'd need to first patch the hole so the saw has something to keep it from sliding all over the door, and of course this only works if you're enlarging the hole to include the entire space of the old lock.
In its currently disassembled state, there is nothing locking the mechanism. You are correct that the C shaped half-circle shaft is what pulls the latch back when turned.
If you cannot push the latch back with your finger, the anti-jimmy device has had a piece break in it.
I had this happen on a bathroom door latch about two weeks ago, probably made by the same manufacturer as the shape of the lock actuator rod and latch actuator are exactly the same.
If you look at it, the lock actuator rod (the center piece you were turning) has a taper section just where it passes through the latch pull which means that during assembly, you manually push the latch back and it passes straight through.
In order to get clearance so the lock actuator rod will pass through, I pried the folded piece that they pass through till I got clearance so the shafts would pull out. I then squeezed the folded piece back together and pushed the latch out. It didn't even require taking the door off the hinges.
Replace the whole door knob/latch assembly with new and you're back in action.
Best Answer
Either the holes to secure the strike plate became very worn and the technician decided to "rivet" it into place or it might be a security addition. Drill those out using a small bit and keep increasing in size until the rivet falls out. You might find that the threads still exist so be careful and you might not have to use rivets to reinstall the strike plate.