Ball Bur SD End Type Radius Cut Type Single Shank Dia 1/4 in Head Dia 7/16 in Head Length 3/8 in Included Angle Not Applicable Overall Length 2 1/8 in Trade Number SD-4 Primary Material Application Cast Iron Ferrous Metals Non-Ferrous Metals Steel Head Shape Ball Shank Length 1 3/4 in Operating Speed - Maximum 40 000 RPM Compatible Tool Type Die Grinder Rotary Power Tool Straight Grinder Head Material Carbide Head Material Grade YG7 Shank Material Steel