IRWIN Tools 1892848 Impact Performance Series 5/16-Inch Turbomax Black and Gold Drill Bit Bulk, 6-Pack Built for maximum durability and long life with impact drivers One-piece construction withstands higher torque loads than standard quick-change bits Exclusive TURBOMAX tip eliminates "walking," delivers 10X faster starts, and stays sharp longer Made from premium high speed steel with black oxide finish for added corrosion resistance Black oxide finish resists corrosion and increases life of extractor