Greenlee® Kwik Stepper® Step Bit, Imperial, #1 Letter/Wire, 1/8 in Diameter Minimum Hole, 1/2 in Diameter Maximum Hole, 3.08 in Overall Length, 13 Steps, 1/8 in Step Depth, 13 Hole, 2 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, 3/8 in Shank, Hex Shank, Split Point, Cobalt HSS Cutting Edge, 10 ga Stainless Steel, Steam Oxide, Applicable Materials: Aluminum, Brass, Copper, Fiberglass, Mild Steel, Plastic, Sheet Metal, Laminates and Wood,