Self-centering, precision-ground tip won't walk on flat or curved surfaces, stays sharp longer, and drills faster than standard high-speed drills. Made from premium M-2 high-speed steel for increased durability. Black and gold oxide coating provides maximum corrosion resistance. Through-hardened chrome vanadium shaft with shot-peened, double-tempered finish is hot-isostatically pressed to resist breakage and extend bit life. Includes 1/16-, 3/32-, 1/8-, 5/32-, 3/16-, 7/32-, and 1/4-inch bits in a plastic case.