Features 1、Made of quality carbon steel material, high hardness and high strength, wear resistance and can provide long service time. 2、Manufactured with quenching heat hardening process for maximum accuracy and stability. 3、High precise concentric shaft design for easy centring, sandblasting surface, prevents slipping, not easy to break. 4、The surface is treated with electrophoretic black technology to prevents rust and corrosion, giving it a higher durability. 5、2 set of specifications available, with high drilling efficiency, 36pcs 75mm and 50pcs 75mm, you can choose according to your demands. 6、Suitable for home, auto repairs, electrical repairs, electronic product repairs, machine repairs, etc.. 7、And you can use it with electric drill, electric screwdrivers and impact screwdriver. Specification These drill bits are made of quality carbon steel material, high hardness and high strength, wear resistance and can provide long service time. Manufactured with quenching heat hardening process for maximum accuracy and stability. High precise concentric shaft design for easy centring, sandblasting surface, prevents slipping, not easy to break. 2 set of specifications available, with high drilling efficiency, 36pcs 75mm and 50pcs 75mm, you can choose according to your demands. Features: Made of quality carbon steel material, high hardness and high strength, wear resistance and can provide long service time. Manufactured with quenching heat hardening process for maximum accuracy and stability. High precise concentric shaft design for easy centring, sandblasting surface, prevents slipping, not easy to break. The surface is treated with electrophoretic black technology to prevents rust and corrosion, giving it a higher durability. 2 set of specifications available, with high drilling efficiency, 36pcs 75mm and 50pcs 75mm, you can choose according to your demands. Suitable for home, auto repairs, electrical repairs, electronic product repairs, machine repairs, etc.. And you can use it with electric drill, electric screwdrivers and impact screwdriver. Specifications: Name: Electric Drill Bit Set Material: carbon steel Type: 36pcs 75mm, 50pcs 75mm (optional) Package size: 185 * 130 * 40mm / 7.28 * 5.12 * 1.57in Package weight: 36pcs: 806g / 1.78lb 50pcs: 880g / 1.94lb Packing List (36pcs 75mm, 50pcs 75mm OPTIONAL): 1 * Electric Drill Bit Set 1 * Plastics Box Package List (36pcs 75mm, 50pcs 75mm OPTIONAL): 1 * Electric Drill Bit Set 1 * Plastics Box