The MILWAUKEE® THUNDERBOLT® 21PC Black Oxide Drill Bit Set offers heavy-duty performance on the jobsite. Black Oxide coating reduces heat build-up and provides corrosion resistance. The thicker core provides ultimate strength and protects against side-load breakage while a specially designed parabolic flute form clears chips and debris fast to keep the bit cool. The 135° split point tip delivers a precision start and prevents walking for fast, accurate holes. MILWAUKEE® THUNDERBOLT® Black Oxide Coated bits are ideal for various drilling applications in wood, plastics, and metals. The set is organized in a customizable accessory case designed for use in PACKOUT™.