SAIT® Depressed Center Wheel, General Purpose, 4-1/2 in Wheel Dia, 0.045 in Wheel Thickness, 7/8 in Center Hole, Arbor Connector, 60 Grit, Medium Grade, Aluminum Oxide Abrasive, Wheel Type Number: Type 27, 13300 rpm Maximum, Resinoid Bond, Applicable Materials: Ferrous and Non-Ferrous Metals