Greenlee DTAPKITM M3-M10 6-Piece Combination Drill and Tap Set Complete hole drilling, tapping, deburring and 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 Made from hardened high-speed steel vs carbon steel for longer life Designed to tap up to 10-gauge metal