The Milwaukee 21-piece Thunderbolt Black Oxide Drill Bit Set offers convenience and heavy-duty performance on the job site. These drill bits are designed for extreme durability and long-life. The Thunderbolt web features a thicker core to provide ultimate strength and protect against side-load breakage. Corrosion resistant coating provides lubricity and resists the corrosion of the tip. A specially designed parabolic flute form clears chips fast, while the 3-Flat Secure-Grip shank holds the drill bit firmly in the drill chuck. The 135 degree split point tip delivers a precision start and prevents walking for fast, accurate holes. The Milwaukee Thunderbolt Black Oxide bits are effective for drilling on curved surfaces and require less effort to drill through metal, wood and PVC. The set comes in a durable carry case and includes bit sizes two 1/16 in., two 5/64 in., 3/32 in., 7/64 in., two 1/8 in., 9/64 in., 5/32 in., 11/64 in., two 3/16 in., 13/64 in., 7/32 in., 15/64 in., two 1/4 in., 5/16 in., 3/8 in. and 1/2 in.