The Milwaukee #2 Step Drill Bit, 3/16"-1/2", Shank Size: 1/4 Inch, Hole Diameter: 3/16 to 1/2 Inch, Coating: Black Oxide, Style: Dual-Flute Step Bits, Cutter Geometry: Dual-Flute, Number Of Steps: 6, Increments: 1/16 Inch, Application: Metal, Plastic, For Use With Cordless Drills In High Speed.