High Quality Materials: This metal wood router bit kit is made of high speed steel, high hardness and not easy to rust, its cutting edge is hardened and ground, so it is sharper and its service life is longer. Practical Function: The screw cap is perfect embedded in the surface of the workpiece, disposable sink hole drilled Smooth, spiral flute with a center drill will quickly discharge chips from the hole. The drill only produces pilot holes. Easy to Use: The drilling length can be adjusted for screws of different lengths simply by loosening and tightening the set screw. Has Many Uses: Countersinks drill bit set for woodworking it is widely used for plastic, PVC, rubber, chipboard, hardwood or wood flooring. This product can only drill holes for male threaded plugs. Package Contents: You will get 8 pcs wood plug drill bits, 5 pcs wood drill bits, 1 pcs hex screwdriver.