Meet your work needs: countersink drill bit set Including 5pcs countersink drill bit and 5pcs replaceable bits offered, 5 Hex. 5 different drill diameter sizes: 2.8mm, 3mm, 3.2mm, 3.5mm, 4mm, counter-bore diameter size: 8mm Detachable and Adjustable: Use the accompanying hex wrench to remove the screws and adjust the length of the countersink hole to adjust the drilling depth of various length screws, improving work efficiency. Two Drilling Methods: wood drill bit set have two drilling methods. You can either drill holes on the surface of the wood or drill holes in the wood, making to give a clean, professional look. Versatility: Provides precise, clean pilot holes in compressed board, plastic, MDF, pine and more. Counter sink bits designed as to work as wood drill bits, perfect for woodworkers, DIY enthusiasts, home repairs and more. Prohibited materials: glass, metal, concrete, plasterboard. Compatibility: Suitable for drilling machines with chucks such as lithium electric drills, hand drills, bench drills, etc. It is recommended to use a center punch for positioning before drilling, and keep the drill vertical to prevent the drill from bending or breaking. If there is any problem, please feel free to contact us. Colour:Orange Material:alloy + carbon steel Size:Shank diameter:8mm Package Contents: 5 * countersink drills (2.8+3+3.2+3.5+4mm) 5 * replaceable drills (2.8+3+3.2+3.5+4mm) 5 * wrenches