Combination Drill/Tap bit made of high speed steel, 1/4 inch quick change hex, up to 10 gauge material thickness, used with mild steel, copper, brass, aluminum. Complete hole drilling, tapping and deburring/countersinking in one operation with power drill saves labor and time. Back tapered beyond tap to prevent thread damage from over-drilling. Deburr/countersink also provided on bit beyond back taper. High quality hex shank to ensure strong connection to drill chuck. Designed to tap up to 10-gauge metal. Quick change adaptor included in both metric and standard kits.