Bosch Bl21A 21-Piece Assorted Set Black Oxide Metal Drill Bits With, Plastic Bosch Black Oxide Metal Drill Bits have been designed to satisfy contractors, electricians and other pros who need solid, reliable bits for general-application drilling in wood, plastic and light-gauge metal. The split-point tip has been engineered for no-skate starts and clean, accurate holes. The bit provides longer life than standard drill bits, thanks to the tip design and black oxide coating. The three-flat shank design on bits 3/16 In. and larger promotes better gripping and guards against slipping. ACCURACY: featuring split-point tip engineered for No-skate, clean and accurate starts in a variety of drilling applications including wood, plastic and light-gauge metal. LONGEVITY: thanks to the unique bit design and heavy duty black oxide coating This set generates less friction and provides longer life than standard drill bits. RELIABLE: The Three-flat shank on bits 3 16 in. And larger promotes better grip and guards against possible slipping. UNIVERSAL: Universal drilling applications Designed for contractors, electricians and tool pros who need accurate and reliable bits for general-purpose use. VERSATILE: included bit sizes: (2) 1/16", (2) 5/64", (1) 3/32", (1) 7/64", (2) 1/8", (1) 9/64", (1) 5/32", (1) 11/64", (2) 3/16", (1) 13/64", (1) 7/32", (1) 15/64", (2) 1/4", (1) 5/16", (1) 3/8", (1) 1/2"