Machining Polyurethanes | Mark Tool Rubber Co, Inc.
WEBNov 1, 2017 · When grinding 55A to 80A durometer polyurethanes, use a tool post grinder in an engine lathe. Low turning speeds (below 150 rpm), with the lathe running in reverse will yield the best results. If you're removing lots of material, first turn the piece down with a cutting tool to within .020 of the finished dimension before grinding.