Features Versatile Set: This 7-piece set includes drill bits for m, 4mm, 5mm, 6mm, 7mm, 8mm, and 10mm screw sizes, providing a comprehensive solution for various woodworking needs. Countersinking: Specially designed steel countersunk and chamfer drill bits create guide holes for accurate and clean screw installation, ensuring professional results in woodworking projects. Efficient : The 5 flute design enables quicker wood chip removal during use, improving efficiency and reducing the time required for drilling and countersinking wood screws. Adjustable Drilling Length: Simply loosen and tighten the set screws to easily adjust the drilling length for screws of different sizes, offering flexibility and convenience in woodworking tasks. Professional Finish: Achieve smooth and flat countersunk s with ly embedded nuts, enhancing the overall appearance and quality of the workpiece. Features: 1、The set includes drill bits for drilling pilot holes, screw sizes are m, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm. 2、Specially designed steel countersunk or countersink guide holes. 3、Drilling and countersinking wood screws without changing drill bits. 4、Just loosen and tighten the set screws to adjust the drilling length of screws of various lengths. 5、5 flute design for quicker wood chip removal during use. 6、Smooth and flat countersunk, and the nut is ly embedded in the of the workpiece. Specification: Item Type: Countersunk Drill Bit Dimension: m x 60mm(L) Chamfer Diameter: 15.8mm 4mm x 75mm(L) Chamfer Diameter: 15.8mm 5mm x 85mm(L) Chamfer Diameter: 15.8mm 6mm x 9m(L) Chamfer Diameter: 15.8mm 7mm x 100mm(L) Chamfer Diameter: 15.8mm 8mm x 110mm(L) Chamfer Diameter: 18.8mm 10mm x 120mm(L) Chamfer Diameter: 18.8mm Shank: 1/4 hex shank Size Error: ±2mm Package List: 7 x Countersunk Drill Bit 1 x Hex Wrench Package List 7 x Countersunk Drill Bit 1 x Hex Wrench