I'm not Lynn, but I know firsthand that it's a decent amount. I had to grid-lap mine like 5-6x using a DMT 325 for it to be totally free of the grainy stuff. That probably equalled out to at least 1/16" I'm guessing.. :shrug:
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I would agree with the 1/16 on the 4K side maybe more and the same on the 8K side these days, maybe less. Doesn't take too long thought with the DMT 325 to get to smooth on both sides and usable.
Have fun.