27/64" Thunderbolt Black Oxide Drill Bit Milwaukee thunderbolt black oxide jobber length drill bits are designed for extreme durability and long life. The thunderbolt web features a thicker core than a standard drill bit, which provides ultimate strength and protects against side-load breakage. A specially designed parabolic flute form clears chips and debris fast to keep the bit cool. A precision start, 135 split point tip starts on contact to keep the bit from walking for fast accurate holes. Excellent for drilling on curved surfaces, requires less effort to drill and is highly recommended for use with portable drills. The 3-flat secure-grip shank won't slip in the drill chuck. Features: 27/64" Diameter 3-Flat Secure Grip Shank Black Oxide Construction Since its founding in 1924, Milwaukee has focused on a single vision: To produce the best heavy-duty electric power tools and accessories available to the professional user. Today, the Milwaukee name stands for the highest quality, durable and reliable professional tools money can buy.