
Premium Materials: The blades are made of high quality alloy, waterproof and corrosion resistant, the blades made of hardened HSS steel are sharper and more durable. Good Design: Adjustable limits of round shank for a wider range of applications, stable tightening effect and easy to use. Removable and Adjustable: Remove the screw with the included Allen key and adjust the length of the countersunk hole to adjust the drilling length of screws of different lengths. Practical: The HSS spiral groove drill bit set with center drill quickly drains the chips from the hole. It can effectively prevent the accumulation of residue and improve drilling efficiency. Versatile: Countersink drill bit suitable for home or professional woodworking, used on wood, plastic, PVC, fiberboard, chipboard, plywood, rubber and more.