MUXSAM 5Pcs #5 #6 #8 #10 #12 HSS Countersink Drill Bit Set Quick Change Hex Shank Screw 4 Of The Most Often Used Sizes For Carpenters, Cabinet, Furniture Makers And Other Wood Working Trades. Drills The Pilot Hole And Recess For Countersinking All In One Step. Fast, Smooth Cuts In All Types Of Wood And Plastic. Loosen Set Screw To Adjust Drill Bit Depth For Variable Screw Lengths. The Drill Bit Is Replaceable.