Black Oxide Step Drill Bit Set (6-Piece)Milwaukee Step Drill Bits with JAM FREE Performance feature a dual flute design delivering up to 2X faster hole times, up to 4X longer life and up to 50% more holes per battery charge than competitors. Ideal for drilling small and large diameter holes in steel and plastic, these bits are Optimized for Cordless Drills in High Speed. The Rapid Strike tip allows for a fast and accurate start that generates less heat, resulting in longer bit tip life.