Triumph® Step Drill, Series: TSD, Imperial, 1/8 in Diameter Minimum Hole, 1/2 in Diameter Maximum Hole, 13 Steps, 13 Hole, 13 Flutes, 1/8 in, 5/32 in, 3/16 in, 7/32 in, 1/4 in, 9/32 in, 5/16 in, 11/32 in, 3/8 in, 13/32 in, 7/16 in, 15/32 in, 1/2 in, 1/4 in Shank, 3-Flat Shank, 135 deg Point, Split/Self-Centering Point, HSS Cutting Edge, HSS, Bright, Applicable Materials: Alloy Steel