Features High quality YG8 alloy cutter head: Ensures exceptional wear resistance, providing durability and longevity for consistent woodworking performance. Complete specifications: Ranging from 2.8-4mm drilling diameter, offering versatility for various woodworking projects, making it a versatile carpentry tool. Surface spray treatment: Provides rust and oxidation resistance, ensuring the longevity of the drill bits, ideal for woodworking and aluminum alloy countersinking. Suitable for wood and aluminum alloy: Versatile functionality for woodworking and aluminum alloy countersinking, making it an essential woodworking tool. Individual case for each drill bit: Offers protection and organization for easy storage and access, enhancing the convenience and durability of the set. Specification: Item Type:Countersink Drill Bit Material:YG8 Alloy 45# Carbon Steel Type:2.8x8mm 3x8mm 3.2x8mm 3.5x8mm 4x8mm Net Weight: 160 g / 5.64 oz(approx.) Package List: Item Type:Countersink Drill Bit Material:YG8 Alloy 45# Carbon Steel Type:2.8x8mm 3x8mm 3.2x8mm 3.5x8mm 4x8mm Net Weight: 160 g / 5.64 oz(approx.) Package List 5 x Countersink Drill Bit 5 x Hex Socket Wrench 5 x Screw