Snoopy, Dave's reference to plating may mean passivation. That is sometimes considered plating altough it is really an acid bath that removes trace amounts of tool steel transfered to stainless when it is formed. I would be almost positive these are made from stainless. The magnet test seems to bear this out. I would like to see how the detail in the lip differs from the original tho, and would still like to know a part # that matches the original 3" deep rings.