.Coated Abrasive Flap Disc, Premium, 4-1/2 in Disc Dia, 5/8-11 UNC Center Hole Thread Size, 80 Grit, Discs are contaminant free, with Iron, Sulfur and Chlorine Weilers Saber Tooth flap discs deliver real performance on stainless steel, aluminum, inconel, titanium and other hard-to-grind metals.