Halflock wroteI will not say more than it was used on heavy industrial storage. The key system was replaced with a more modern system. Cylinders for this padlock are not available in newer keyways.
I’ll give you a little background on that lock. IIRC, it was designed in 1977 and submitted as a competitor for the S&G 831B. It uses the same exact cylinder as all of the military padlocks. The case is sand cast bronze and what you call the top cover was referred to as a ‘manhole cover’.
In those days bid summission testing was done at Natick, MA. and prior to submission I actually took one of the first models there for them to do a pull test for us. Again, IIRC it took 7800 pounds of force to pull the shackle.
The original models did not have the hardened pins around the edge. There were later models that had 5 pins on each side and eventually it ended up with the number shown in your example. I may still have one without any pins in my collection.
Naturally it did not exceed the test requirements and the 831B remained the primary military padlock. The lock was sold commercially and made available with all of the Medeco keyways of the day. You should be able to get an M3 version of the current military padlock cylinder and slip it right into place in that lock.
BBE.
[unknown]
