HHIP 2000-0031 5 Piece (82 Degree-1/4~1 Inch) HSS Countersink Set High speed steel or Cobalt; 5 PC. SETS: 1/4, 3/8, 1/2, 3/4 & 1" 82 degrees; HSS For portable and machine work when operated at comparatively high speeds 5 PC. SETS: 1/4, 3/8, 1/2, 3/4 & 1"Single flutes will countersink holes much smaller than multi-flute tools; High speed steel or Cobalt