UKC

Just had a delivery of Petzl Bolt Hangers, first box was (as ordered) Stainless Coer marked 316L so no problems there.

The second box were not Coer's and they are marked with 12.2, 12.3 and 13.3 on the back of the hanger.

Of course they are not the 316L stainless ones I ordered, I'm guessing they are not fit for use in the outdoors as they may not be stainless. I just need to check if anyone knows what the numbers mean, as perhaps they are old stock and may well be ok?

I’ve got some 10 and 12mm with 18.3 and 18.4 on them, so I’m interested to hear a response from someone. 

The 12.3, 13.3, 18.4, whatever, are the manufacturing dates, in the format xx.y where xx = year, y = quarter.

If the hanger isn't stainless it should say "steel" on it, but maybe that wasn't stamped back in 2012. Worth an email to Petzl i guess

Thanks for the explanation, they look like all the other stainless hangers I have and use. They are obviously old stock so difficult to be 100% sure that they are stainless, the numbers just threw me a bit...

You can check if they are stainless with a magnet if unsure, austenitic stainless steels such as 316 are essentially non-magnetic, plated carbon steel the opposite.

Ask the shop you bought them from, if they can't tell you, they can't be trusted. You might as well be using one of those import ropes from a well know on-line retailer.

Don't know why this got a down vote, it's a reasonable suggestion.