Anchor chain identification

[4fun1]

Trying to figure out what type of chain I have. It looks like it is marked with an "A M". It is either 3/8 or 10mm.

I haven't been able to find anything online.

 

[rgano]

Have you considered asking the boat's manufacturer?

 

[Comodave]

Break out the calipers and measure it. Then call either the boat manufacturer or the windlass manufacturer and see what they know.

 

[Shrew]

Acco Marine stamps their chain types

TC = Tuna Chain
MC = Mooring Chain
Acco Grade 70 = A7
Acco Grade 40 = A4
BBB = 3B

Is there a chance that is an old Acco Marine (AM) chain??