Diameter 2.5mm Hex Shank Drill Bit Set. 4-piece set includes a bit set for drilling pilot holes for screw sizes #6, #10, #13 and #16. The standard 2.5mm hex drill bits shank is compatible with quick change. Function: Can drill the screw holes and stay on the same axis, after screwing the screw nut under the board Special steel plywood for cutters or counter pilot bores. The drill length can be adjusted for different screw lengths simply by loosening and tightening the grub screw. Material: High Speed Steel - Christmas Gift for Dad/Father, Husband, Boyfriend, Man, handyman. Applies with collet or joint drill, suitable for drilling in hardwood and wooden floor, wood screw machine screw. Features: Black Chamfer Drill Bit Body Material: 45 Steel. Color: As the picture shows. Size (matching bit size): #6: 3mm #10: 3.5mm #13: 4mm #16: 4.5mm Shank: 2.5mm diameter hex shank. Features: High quality product, sharp and durable. 4 piece set includes bits for drilling pilot holes for screw sizes #6, #10, #13, #16, including a mini hex wrench . It can drill the screw holes and stay on the same axis, after screwing the screw, nut under the board. Apply with pliers or joint drilling machine, suitable for drilling in hardwood and parquet, machine screws for wood screws. Function: can drill the screw holes and stay on the same axis, after screwing the screw nut under the board. < br> Note: - The color may vary slightly due to the lighting or brightness of your screen. - Due to hand measurement, sizes shown may vary from 0 to 3mm which is completely normal. - The item is quite sharp, please keep away from children. - The color of the actual item may vary from the pictures, depending your computer's display and brightness settings. THANKS ! ! Contents: 4 drill bits. 1 hexagonal shank.