... and core sharp(like cycle, square, hexagon, etc.),Hardness: increase with the Numfrom 2P to 30PColor: having different colorGray ,red ,white , black ,green ... , brown,ectGrit:from 46# to 3000#main applications:various electroplate, stainless steel ,alloys surface polishing and ... strip coating ,Machine fittings rust and burr cleaning ;and porcelains. ceramic , ...