KEO 53512 Cobalt Steel Single-End Countersink, Uncoated (Bright) Finish, 82 Degree Point Angle, Round Shank, 5/16" Shank Diameter, 1/2" Body Diameter Cobalt steel tools are similar to high-speed steel, but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications Round shanks allow use with a wide variety of toolholding systems When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging 82 degree angle