pMARXMAN Carbide Burr, General Purpose, Series 597, 38 in Head Dia, 516 in Length of Cut, Ball Shape SD Head Shape, Standard Cut Type, 14 in Shank Dia, Solid Carbide Head, Bright Head Coating, 38000 rpm Maximum, Applicable Materials Cast Iron, Ferrous Metals and Steel, SD3 Industry Specificationp.