6pcs HSS 1/4 Inch Hex Shank Combination Drill Tap Countersink Bit Set M3 M4 M5 M6 M8 M10 Metric Deburr Chamfering Bits 6pc drill tap countersink deburr set metric combination drill m3 m4 m5 m6 m8 m10 hss 1 4 inch hex shank deburr countersink bits