Our THUNDERBOLT Black Oxide Jobber length drill bits are designed for extreme durability and long life. The MILWAUKEE THUNDERBOLT web features a thicker core than a standard drill bit to provide ultimate strength and protection against side-load breakage. A specially designed parabolic flute form clears chips and debris fast to keep the bit cool. The 135 DEG Split Point tip starts on contact to keep the bit from walking for fast, accurate holes. Our drill bits are excellent for drilling on curved surfaces and require less effort to drill perfect for work with portable drills. The 3-Flat Secure-Grip shank won't slip in the drill chuck and there is a reduced shank diameter for use in 3/8in chucks. The 29-Piece THUNDERBOLT Black Oxide Drill Bit Set comes with: 1/16in through 1/2in by 64ths.