#1 Step Drill Bit, 1/8 - 1/2-In.
The Milwaukee #1 Step Drill Bit, 1/18"-1/2", Shank Size: 1/4 Inch, Hole Diameter: 1/18 to 1/2 Inch, Coating: Black Oxide, Style: Dual-Flute Step Bits, Cutter Geometry: Dual-Flute, Number Of Steps: 13, Increments: 1/32 Inch, Application: Metal, Plastic, For Use With Cordless Drills In High Speed.