Material High Carbon Steel Finish Type Black Nitriding Stem Type Threaded Surface Recommendation Wood About this article 7+1PCS Different ForestWood drill bit of 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm and a hex wrench. You can use the hex key to loosen and tighten the screw and adjust the length of the cutter. it can also use for disassembly and installation of drill bits HSS SteelOur Wood drill bits are made of HSS steel, forming a strong and sharp countersunk hole, with high hardness and good wear and heat resistance, which can be cut in any direction to ensure precise flat-bottomed holes. and clean Tricuspid Centering & Five Edge ChamferThe three-point cutter ensures the drill bits will not shift, slip, good for accurate and fast drilling. Five-edged chamfer design of countersink bit clears wood and debris more quickly and automatically Applicationfor mounting the spherical tip of the drawer; perforation of wood products, plastic products, wood and plywood Use with Power ToolsSuitable for drill press, hammer drill, bench drill, vertical drill, column or portable drill and mobile band drill Have a great time shopping!