Combination drill and tap bit set RUIMI metal deburr countersink drill bit 1/8''-3/8'' Hex Shank HSS Drill Bit & Screw Tap of Imperial Unit Made from hardened high-speed steel vs carbon steel for longer life Back tapered beyond tap to prevent thread damage from over-drilling Deburr/countersink also provided on bit beyond back taper Complete hole drilling, tapping, deburring and countersinking in one operation with power drill saves labor & time 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 001 6-32NC(3.5mm) about 8g 002 8-32NC(4.2mm) about 8g 003 10-24NC(5mm) about 9g 004 10-32NC(5mm) about 9g 005 12-24NC(5.7mm) about 10g 006 1/4-20NC(6.35mm) about 11g Material: HSS Shank diameter: 6.35mm hex shank(1/4&#034;) Color: silver tone Full length: 56mm Blade length: 28mm Shank length: 30mm 6x Hex Shank HSS Drill Bit &amp; Screw Tap of Imperial Units