HHIP 2001-2000 1 Inch 82 Degree 3 Flute HSS Countersink Cutter Diameter (Inch) 1; Shank Diameter 1/2 Length Approx. 3-1/2 Utilized in countersinking screw and rivet heads and for centering lathe work 3-Flute eliminates chatter in most applications, while providing better accuracy than a single flute countersink.; High speed steel