SAIT Pipeline Depressed Center Wheel, High Performance, 6 in Wheel Diameter, 1/8 in Wheel, Thread Connector, 24 Grit, Coarse Grade, Aluminum Oxide Abrasive, Wheel Type Number: Type 27, 10200 rpm Maximum, Resinoid Bond, Applicable Materials: Ferrous Metals, 5/8-11 Center Hole Thread, Wheel Hardness: R, Black Wheel, Reinforced: Yes, Specifications Met: ANSI B165.1, ANSI B165.2, ANSI Z87.1, OSHA 29CFR 1910.1200