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 The Competition. Ideal For Drilling Large and Small-Diameter Holes In Steel and Plastic, These Bits Are Optimized For Cordless Drills In High Speed. The Rapid Strike™ Tip Allows For Fast, Accurate Starts That Generate Less Heat, Resulting In Longer Bit Tip Life. Black Oxide Coating Also Enhances Durability, Hole Quality