Doug MacQueen wroteThere are the key change and hand change versions of both the Gr 1 and Gr 2 locks. 3 (302) and 4 (402) wheel locks in the Gr 2, not sure if there was a 4 wheel Gr 1.
I was thinking the same, more or less. There should be several ways to categorize safe locks.
3 wheels or 4 wheels; I assumed this was 302/402
Hand Change versus Key Change. I assume this is the “K” in some model designations.
Group 1 and Group 2. Perhaps the former is the “MR” in models such as MRK302
X-Ray-resistant wheels versus ordinary wheels (the latter might be metal or plastic but that’s probably a manufacturing choice rather than a model specification).
Now, that’s 16 models. Of course we can omit some, for example x-ray-resistant group 2 doesn’t make much sense.
What’s curious is a 1988 training video I just got on eBay that states there were 9 models and the details are spelled out in NS4004. So I’m curious about which ones they made or didn’t make, and the model designations. And, as I mentioned, parts/assembly diagrams.
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