Three Flats Shank HSS Drill Bits Manufacturing:Milled Material:HSS,HSSCO ... :1/16" to 1/2" Long life, fast drill speed Three Flats Shank HSS Drill Bits* 118° or 135° Quick-Cut ... , stainless steel and even heat treated or high alloy metals * three flats, 1/2" shank black& bronze oxide, silver& deming according ...