SAIT® Sait Z-Tech™ Depressed Center Wheel, High Performance, 5 in Wheel Dia, 0.045 in Wheel Thickness, 7/8 in Center Hole, Arbor Connector, 36 Grit, Extra Coarse Grade, Zirconia Abrasive, Wheel Type Number: Type 27, 12200 rpm Maximum, Resinoid Bond, Applicable Materials: Ferrous Metals