Milwaukee® Grinding Disc, Type 27 Reinforced, 4-1/2 in Dia, 1/4 in Thickness, 7/8 in, A24R Grit, Coarse Grade, Aluminum Oxide Abrasive, 13580 rpm Maximum, Resinoid Bond, Applicable Materials: Metal, Ferrous Alloy, High Tensile Material, Stainless Steel and Wood