Material Made of high speed steel (HSS), high hardness and rust resistance for extended service life.6 Sizes SetM3 (0.5mm), M4 (0.7mm), M5 (0.8mm), M6 (1.0mm), M8 (1.25mm), M10(1.5mm). 6 steel drill bits, which perfectly meet your different needs.A sharp, hardened drill bit induction, resistant to slightly induced wear, to ensure puncturing speed, improve work efficiency.High EfficiencyComprehensive drilling, tapping, deburring and countersinking in one operation saves processing steps and time costs, improves work efficiency.ApplicationSuitable for drilling wood, plastic, thin copper, aluminum and other soft metals (5-6mm), not for hard materials (e.g. steel sheet).PrecautionsWhen drilling a hole, you should inject water at the same time to cool the forest. 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.