Material: High Speed Steel 4341, Made of High Speed Steel (HSS), high hardness and rust resistance for long life. Size: M3x0.5, M4x0.7, M5x0.8, M6x1, M8x1.25, M10x1.5. 6 set sizes, which perfectly meet your different needs.A sharp, induction hardened drill bit, resistant to lightly induced wear, to ensure puncture speed, improve work efficiency. The Complete drilling, tapping, deburring and milling in one operation save processing steps and time costs, improve working efficiency. 6 steel bits , suitable for drilling wood, plastic, fine copper, aluminum and other soft metals (5-6 mm), not for hard materials (eg sheet steel). When you drill a hole, you need to inject water at the same time to cool the drill bit. This will help you increase the value of the exercises. If you cannot cool the drill bit when drilling holes, the drilling speed should not be too high and you should not drill too frequently.