... 2)Can be mounted in a drill grinding head1)wool felt bobs,polishing felt bob 2)Can be mounted ... density felt, is cut by mechanical stamping mill, made of various shape felt bob. 2. Felt bob have Elasticity, ... inner, outer, Corner, groove, arc, cone angle of the inner wall of the mill special mold polishing, nylon, stainless steel, ... carving, jade carving, ceramic arts, etc. grinding head of wool felt