PCD Cup Wheels are manufactured with premium polycrystalline diamonds, thus the name PCD. While these grinding discs are very wear-resistant, they are not impact-resistant. To guarantee a long lifespan out of your PCD grinding wheel it's imperative that you avoid joints, bolts, and anything made out of steel. Syntec PCD Wheels work great for removing thick coatings, epoxy, and other membranes all without gumming up.