Milwaukee® Thunderbolt® Black chemical compound distributor length drill bits are designed for extreme sturdiness and long life. The Thunderbolt net options a thicker core than a typical bit to supply final strength and shield against side-load breakage. A specially designed parabolic flute type clears chips and rubble quick to stay the bit cool. The 135° split purpose tip delivers a preciseness begin and prevents walking for quick, correct holes. Effective for drilling on recurvate surfaces, city Thunderbolt Black chemical compound bits need less effort to drill through metal, wood and PVC, and are extremely counseled to be used with moveable drills.