So just over a week ago I went to this store and rekeyed it. Two Kwikset (KW1) locks on a side door, one Schlage (SC8) knob on another side door and two old mortise locks (Y1) on the commercial doors on the front of the store. I tested everything before I left and it worked great.
The customer called yesterday and said his keys did not work in the front door anymore. He opened the store but he could not lock the doors at the end of the day. I was jam packed on my schedule, but nevertheless, I fit him in at the end of the day. I take pride in my work and I would hate to jepordize someone’s business because of a fuck up of mine.
I go out there and sure enough, his key did not work in the lock. Well, kind of. The outside lock on the door, it would only turn maybe 1/8th of a turn clockwise, but not counterclockwise. The inside lock would not turn at all. I pulled the locks off and took them plus his key to my van.
When I originally keyed up these two locks, I had used a General Lock set of factory keys. The bitting on the key was 23236. I still had the factory keys and I tried those. They did not work. His key no longer worked in the front lock. I shimmed both of the locks opened and pulled the cores out.
To my surprise, I found that the 5th pin was well below the shear line. The other 4 pins were just slightly above the shear line. When I tried to key these locks originally, I had to drop each pin length by one full cut, so the pinning inside the lock was 12125. Maybe the plug diameter was smaller than .5? They were pretty old locks.
Anyways, I took the 5th pin out and measured it with my calipers. It measured .258. According to the LAB chart, this corresponds to Yale #4.
This really confused me. How could I have pinned the lock with a #4 pin in the 5th chamber even though the 5th cut on the key was a 6? The .276 pin is gold, but the .258 that was in there was red.
I just don’t see how I could have pinned the lock wrong, tested it, and it worked. I also don’t see how the customer could have been using his key for over a week with no issues but then suddenly have a problem after a week. But how does this explain that the outside lock could turn just 1/8th of a turn but only clockwise? The only time I have seen something like that was when the mortise cylinder was screwed in too tight.
One of my thoughts was sabotage. I don’t really think it is likely, but perhaps someone pulled the locks off and switched the last pin. Or maybe the cores were so worn down that there was some movement with the key and I just didn’t notice it when I keyed them originally, so I dropped the last pin from a 6 to a 4. I only remember dropping it to a 5 though.
Well, I ended up just putting the right pin in the 5th chambers of both locks and reinstalled the lock. The customer was happy his doors could lock again and I went on my way. Still, it makes me wonder what happened. When I was testing, I did notice that the peak at the tip of the key brought the 5th pin to the shear line, but made the others either above or below the shear line. Maybe that has something to do with it. I did use some Tri-Flow on all of these locks, so I don’t think they were sticking.