6Pcs Countersink Drill Bit Set #6, 8, 10, 12, 14, Tapered Counterbore Drill Bits Specification: Corresponding Drill Size: Package: Unit Conversion: 1mm= 0.039in *6pcs countersink drill bit set for the drilling equipment with a chuck or connector for drilling in hard wood. *Includes a 6-piece set of taper drill #6 (2.38mm), #8 (2.78mm), #10 (3.17mm), #12 (3.56mm), #14 (3.97mm) and a allen wrench. *Made of high-speed steel 4241 (titanize) + # 45 steel for durability. *Carrying a hex wrench, the tapered bit's pointed tip and wide cutting edge quickly drills clean pilot holes to ensure a tight fit for screws. Smoothly countersinks holes in both soft and hard woods and drills tapered holes for screwing. *Suitable for drilling machines with chucks or couplings for drilling holes in hard wood and wood ply. NOTE- On the same axis, the screw cap lies below the plane of the board after screwing!