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. Black oxide coating also enhances durability, hole quality and bit life. for user convenience and accuracy, each bit has laser-engraved reference marks you can see while drilling. The 3-flat Secure-Grip shank ensures a solid connection with the drill chuck. The Milwaukee RED HELIX Cobalt 23PC Drill Bit Set is engineered for extreme durability and longer life in hard metal applications. The Milwaukee Cobalt drill bits are designed with a VARIABLE HELIX that includes an aggressive 35° Helix Angle which ends at 15°. The drill bits have QUADEDGE TIP to decrease heat buildup and drill faster. The 135° split point tip delivers a precision start and prevents walking for fast, accurate holes in Hard Metal, PVC and wood. The tapered drill bits feature a new ENHANCED TAPERED WEB that strengthens the bit's core to increase flute durability. The cobalt twist drill bits are ideal for tough applications, providing up to 15X life vs. Black Oxide Drill Bits.