Material: 4341 high speed steel, made of high speed steel (HSS), with high hardness and rust resistance, and long service life. Size: 6 sizes, fully meet your different needs. Induction hardened cutting edge drill resists slight abrasion, ensures drilling speed and improves work efficiency. Complete drilling, tapping, deburring and countersinking with one click can reduce processing steps and time costs, and improve work efficiency. 6 steel drill bits, suitable for drilling wood, plastic, thin copper, aluminum and other soft metals (5-6mm), not suitable for hard materials (such as steel plate) . When drilling, it is necessary to inject water at the same time to cool the drill bit. This will help you increase the value of your practice. If the drill bit cannot be cooled during drilling, the drilling speed should not be too high and drilling should not be too frequent.