Tiger Depressed Center Wheel, Performance Line Superior Life and Cut, 9 in Wheel Dia, 1/4 in Wheel Thickness, 7/8 in Center Hole, Arbor Connector, 24 Grit, Coarse Grade, Ceramic Alumina Abrasive, Wheel Type Number: Type 27, 6600 rpm Maximum, Resin Bond, Applicable Materials: Tool Steel, Inconel, High Nickel Alloy, Titanium, Armored Steel, Stainless Steel and Hard-to-Grind Metals, Wheel Hardness: R, ANSI B7.1-2010 Specifications Met.Weiler’s high quality line of grinding wheels help metal fabrication professionals get the most demanding jobs done right and done fast.