Master pin rendered lock inoperable

[WilsonTrucking]

So a few weeks ago I picked up a bunch of Kik locks from my local habitat for humanity restore and one of them was a real pita. Key wouldn't even go into the lock, got zero feedback from any pin and couldnt get pin 4 to lift at all. Finally opened her up from the back to find the top cap had popped partially off, 4 springs trapped under it sideways and when I gutted the thing there was a very thin master pin atop the key pin in chamber 4 that had gone askew and jamed up the keypin, hence why I couldn't get the key to go in. Is this a common issue when master keying a lock? Also never did find that 5th spring.

[femurat]

I've played with some mastered locks and never had this issue. Maybe someone tried to take it apart and put it back together as good as he could.

An issue I had after picking a mastered lock was a master wafer falling out of its chamber. This could have been a problem if the lock was in use because neither the operating key nor the master key would have worked. Luckily for me it was just a practice lock I had in my hands.

Cheers

[demux]

It's also possible that whoever last owned/serviced the lock did not properly master it. Lock manufacturers specify the smallest allowable master pin in their keying systems to keep stuff like this from happening. Schlage, for example, is a two step system, which means the smallest master pin one should use is a coded 2 size, and only increments of two should be used (e.g. each chamber maintains even/odd parity when master keying). If you use something smaller than the manufacturer specified minimum, you can run into problems like this (as well as other bad things).

Interestingly, this is also a known issue with the Best A3 pinning system - it's a one step system, but the number 1 master pin is too small and is known to have issues with flipping sideways in the pin chamber and jamming up the core.

[GWiens2001]

As stated above, there should never be a one-step increment when master keying a lock. The very thin wafers can sometimes slip between the plug and the shell, jamming the lock with both friction between the surfaces and by preventing the key pin from being able to be lifted above the shear line as needed for the key to fully enter the keyway.

Gordon

[cledry]

As stated above, there should never be a one-step increment when master keying a lock. The very thin wafers can sometimes slip between the plug and the shell, jamming the lock with both friction between the surfaces and by preventing the key pin from being able to be lifted above the shear line as needed for the key to fully enter the keyway.

Gordon

Unless it is a 1 step system like Kwikset or Corbin.

[WilsonTrucking]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

[demux]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

Sure, the step is just the multiplier, not the exclusive size you can use. So in a 1 step system valid master pin sizes are 1, 2, 3, 4, etc. In a 2 step system they are 2, 4, 6, 8. Coded sizes of course. Basically a 2 step system means you have to maintain even/odd parity in each chamber (e.g. you can't have a coded 5 cut on the change key and 2 on the master key). A 1 step system has no parity restrictions.

[GWiens2001]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

Sure, the step is just the multiplier, not the exclusive size you can use. So in a 1 step system valid master pin sizes are 1, 2, 3, 4, etc. In a 2 step system they are 2, 4, 6, 8. Coded sizes of course. Basically a 2 step system means you have to maintain even/odd parity in each chamber (e.g. you can't have a coded 5 cut on the change key and 2 on the master key). A 1 step system has no parity restrictions.

There is a difference between "could not" and "should not".

Gordon

[cledry]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

Not if you want both the change key and the master key to work. A 3B + 1T is not the same as a 2B + 2T.

[demux]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

Sure, the step is just the multiplier, not the exclusive size you can use. So in a 1 step system valid master pin sizes are 1, 2, 3, 4, etc. In a 2 step system they are 2, 4, 6, 8. Coded sizes of course. Basically a 2 step system means you have to maintain even/odd parity in each chamber (e.g. you can't have a coded 5 cut on the change key and 2 on the master key). A 1 step system has no parity restrictions.

There is a difference between "could not" and "should not".

Heh, yeah I was debating getting into that but decided not to go there. I've actually done it before myself, I was mastering a system with very cheap knockoff Schlage cylinders where if you used the specified two step system, there was a ton of unintended key interchange, so I bumped it up to a 3 step. As long as you know what you're doing, and are willing to sacrifice the extra change keys, sure you can do it. Just make sure it's well documented...

[demux]

Even if it was a 1 step system, couldn't you go 2 anyway? Just use a smaller key pin and larger master?

Not if you want both the change key and the master key to work. A 3B + 1T is not the same as a 2B + 2T.

They're not the same, but you could have both in a 1 step system. In this example, the master key would have a 4 cut in this chamber, and there would be two change keys, with cuts at 2 and 3. Although it's entirely possible I missed WilsonTrucking's point in the question. If he's talking about changing out pins in an existing system, and expecting the existing keys to still work, then you're absolutely right.