Does anyone remember the exact year UL split Group 2 and introduced the 2M listing for mechanical safe locks? My bench notes say 1985 tied to a UL 768 revision, but I’ve seen 1987 cited — looking for a precise source to pin this down.
Pretty sure it was 1985 — my UL 768 revision bulletin dated Oct ’85 adds “Group 2M — manipulation‑resistant,” and the first UL White Book that lists 2M is 1986, so 1985 in the lab, 1986 on the bookshelf. If you want a clean cite, I can grab a scan of the revision header or you can pull the 1986 White Book entry for combination locks to match it.
I’ve got the Oct ’85 UL 768 change sheet and it’s the one that introduces 2M — “Group 2M — manipulation resistant” — so your 1985 note tracks. The 1987 you’re seeing is likely the effective date some manufacturers used in their listings, . If you want a cite, pull the UL 768 revision history here: https://ulstandards.ul.com/standard/?id=768 — do you have a scan of your bulletin?
I’d call it 1985 for the standard, with 1986 when it shows up on what folks were buying; @grantf_53’s lab date tracks, and the “’87” is likely catalog lag. Quick verify: the 1986 S&G book shows the 6730 with “2M” on the ring, and UL Product iQ has the issue date — want me to dig a scan?
Leaning 1985 for the standard; my S&G price list dated 3/86 is the first factory doc I see with “2M” on the 6730/6741, and the 1986 UL directory shows it too. Do you have an '86 S&G or LaGard catalog to check the footer date? @grantf_53 is right that '87 is just catalog lag from distributors.
I use the Underwriters Laboratories Burglary Protection Equipment Directory preface as the tie-down — my 1986 printing flags the addition of 2M in the front matter with an early ’86 month stamp, which lines up with your 1985 note and explains the ’87 sightings. If you want a clean citation, that single preface page is perfect; do you have that volume handy, @grantf_53?
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