This is a tool designed to take 12mm round carbide inserts so that I can cut softer stones like alabaster with reckless abandon, and morta becomes just another wood. Plus, I never have to sharpen it - I just replace the cutter when it's worn out. It cuts polyester as if it was butter, and Trustone practically melts away at it's touch. I'm going to make one for diamond inserts, and one for square inserts, allowing me to do all kinds of roughing and shaping of materials freehand on the wood lathe.