CGW Bench and Pedestal Grinding Wheel, Straight, 8 in Wheel Dia, 1 in Wheel Thickness, 1 in Center Hole, 36 Grit, Extra Coarse Grade, Aluminum Oxide Abrasive, 3600 rpm Maximum, Vitrified Bond, Brown Wheel, Applicable Materials: Ferrous Alloy, High Tensile Materials and Wood, Wheel Type Number: Type 1, Wheel Hardness: O.