IRWIN 91148 Reduced Shank Bit Silver and Deming Drill Bit, Spiral Flute, 3 in L Flute, Flat Shank, 1/2 in Dia Shank                   M-7 high-speed steel for strength, heat resistance and wear resistance when drilling in wood, metal or plastic. Can be used with keyless chuck. Three-flatted shank design provides better chuck grip and reduces slippage. All Silver and Deming bits are 6 in long and feature a 1/2 in reduced shank that fits all 1/2 in drills.