Since people are asking, I will post here. I just diamond-coated my worn-out clamps myself, it worked out fine. What you need: 1200 crit diamond powder, 1200 is very fine, should have used a little coarser crit. About $8 for a small bottle. brush-on super glue fine brush (tips: look into your wife's make-up box to steal one, those are the finest brushes and perfect for diamond coating) It is very simple, clean up the clamp surface, brush on a thin layer superglue, then spread on a layer of the diamond powder using the fine brush, wait for 24 hrs, it grips the string like new, mine is still working great after a few stringing jobs, and not sure if it can last a few hundred jobs.