Depressed Center Wheels, Abrasive Wheel Type Type 27, Abrasive Wheel Diameter 6 in, Thickness 0.125 in, Arbor Hole Size 7/8 in, Abrasive Material Zirconia Alumina, Abrasive Grit 24, Max. RPM 10,185 RPM, Series BlueFire, Grade Extra Coarse, Application Ferrous Metal, Gray Iron, Stainless