Here is a photo of Vic Diehl's Type X chain. Of the ones that I have examined, the burnishing didn't hold well on the Type X links. Whether it was the lack of pebbling in the background of the links, or perhaps the heavy nickel content of these assemblies, I'm not sure. Perhaps someone else would have a theory. You can see the same in Vic's chain as well.

Links4.jpg (49.29 KB, 853 downloads)