Weiler 50196 4-1/2" Tiger Ceramic Abrasive Flap Disc, Angled, Phenolic Backing, 40C, X-Lock Arbor Hole (Pack of 10)Top coated for cool grinding, protecting high value parts from heat discoloration. Prevents loading on soft alloys like aluminum. Contaminant free (contains less than 0. 1% Fe, S, Cl). Conical disc shape maximizes surface contact for aggressive stock removal on flat surfaces. Ceramic alumina (CA) grains are self sharpening micro fracturing crystals that expose sharp edges, maintaining a high cut rate for the life of the grain.