Material: high carbon steel material, quenching, high hardness, good abrasion resistance and durability. 7 size: 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 10mm, chamfer diameter is 15.8mm, L-shaped wrench, and can meet all your requirements. Easy to use: just loosen and tighten the mounting screws to adjust the drill length for screws of different lengths. Suitable for wood and plastic Sleeve depth adjustable with wrench. Scope of application: Woodworking countersinking drill bits are widely used in plastic, PVC, rubber, parquet flooring , hardwood (hardness less than 25 degrees) or parquet. Quality service: If you have any concerns about this product, you can contact us by email and we will get back to you within 24 hours. Material: high carbon steel material, quenching, high hardness, good abrasion resistance and durability. 7 size: 3mm, 4mm, 5mm , 6mm, 7mm, 8mm, 10mm, chamfer diameter is 15.8mm, L-shaped key, and can meet all your requirements. Easy to use: simply loosen and tighten the mounting screws to adjust the drilling length for screws of different lengths. Suitable for wood and plastic Sleeve depth adjustable with wrench. Scope of application: Woodworking countersinking drill bits are widely used in plastic, PVC, rubber, parquet flooring , hardwood (hardness less than 25 degrees) or parquet. Quality service: If you have any concerns about this product, you can contact us by email and we will get back to you within 24 hours.