- Summary of benefits: This adjustable countersunk drill bit set is designed to control drilling depth and ensure accuracy. It supports step drill, tapping, and screw step drill functions, and uses an alloy head for durable, reliable performance. - High quality materials: The set is made from high quality alloy steel, hard to crack, high temperature resistant, flexible, durable and long lasting, with scratch resistance. Manufactured to strict quality standards, the improved design helps extend service life. - Wide applications: A versatile direct replacement to meet a range of needs. The package includes 5 adjustable countersink bits in sizes 8x8x4, 8x8x3.5, 8x8x3.2, 8x8x3, and 8x8x2.8, providing convenient options for different tasks. - Package contents: 5 pieces for adjustable countersink bits. - Use scenarios: Ideal for woodworking, metalworking, and general home improvement projects. Use to countersink screw heads flush with the work surface, prepare pilot holes with controlled depth, and perform tapping or screw steps as required.