Ball Bur SD, Cut Type Single, Shank Dia. 1/4 in, Head Dia. 5/16 in, Head Length 5/16 in, Included Angle Not Applicable, Overall Length 2-1/32 in, Trade Number SD-2, Primary Material Application Cast Iron, Non-Ferrous Metals, Steel, Head Shape Ball, Operating Speed – Maximum 68,000 RPM, Coating Bright (Uncoated), Head Material Carbide, Head Material Grade C2 Submicron, Shank Material Steel