That is true for the small ring! They are seamlessly rolled or forged but the large ring has to get through it somehow, so it starts its life as a piece or 'wire' which gets formed and its ends are then joined by electric resistance welding (look up 'chain making' on YouTube).
Today, I inspected all the large rings of the double ring pairs I have with our winch and all of them show the tell-tale signs of a weld opposite of the stamped name 'Tost'. At least a close visual did not show any cracks. Maybe a simple 'dye-pen test is in order.

Uli
'AS'


I seem to remember having read that the rings are made that way without any form of welding now. I suppose you could get the exact method used if you agree to pay for the technical norm:

http://standards.globalspec.com/std/...7/din-ln-65091

It's cheaper than ordering from the original German institute: http://www.din.de/en/getting-involve...din21:84399512