Features 1、Adjustable Depth: The drill bit set can adjust for different screw lengths, creating consistent counterbore holes in wood to defend work surfaces and prevent chip clogging. 2、Hard Alloy Steel Construction: Made from hard alloy steel, the drill bit set has a hardness of HRC 50 to 54, providing outstanding cutting abilities, high durability, and excellent wear resistance. 3、Perfect Counterbore Holes: Make perfect counterbore holes for flathead and plughead screws without splitting wood, enjoying clean projects with just the drill head set. 4、Versatile Specifications: Available in 8 x 8 x 4, 8 x 8 x 3.5, 8 x 8 x 3.2, 8 x 8 x 3, and 8 x 8 x 2.8 sizes, giving you the flexibility to work with various sizes. 5、Efficient Design: The drill bit set is designed to efficiently produce counterbore holes, saving you time and effort on your woodworking projects. Specification Item Type: Countersink Drill Bit Set Material: Hard Alloy Steel Size: Approx. 8 x 8 x 4mm / 0.31 x 0.31 x 0.16in Size: Approx. 8 x 8 x 3.5mm / 0.31 x 0.31 x 0.14in Size: Approx. 8 x 8 x 3.2mm / 0.31 x 0.31 x 0.13in Size: Approx. 8 x 8 x 3mm / 0.31 x 0.31 x 0.12in Size: Approx. 8 x 8 x 2.8mm / 0.31 x 0.31 x 0.11in Package List 5 x Drill Bits 5 x Fixing Screws 5 x Wrenches 5 x Hex Wrenches 5 x Storage Tubes