Bosch CO14 Cobalt Metal Drill Bit Set, 14-PieceBosch Cobalt Metal Drill Bits provide 4X longer life than standard high speed steel drill bits, plus they provide outstanding performance in stainless steel. These have been engineered for contractors and other pros who need solid, reliable bits for demanding drilling applications in stainless, cast iron, and high density metal. These bits also are useful for general application drilling in high carbon steel and light gauge metal, as well as wood and