【Sturdy and Rustproof HSS】Made of high quality HSS, it cuts thin materials quickly. HSS provides extreme durability, and the drill bits are rustproof. At the same time, our drill bit is suitable for electric screwdrivers. 【Application】Step drill bit suitable for DIY, home and construction. It is very suitable for drilling holes in a variety of materials such as steel/ brass/ wood/ plastic/ thin iron plate/ aluminum materials/ insulation plate/ PVC plate, etc. Only suitable for ordinary aluminum, iron and steel plates, not for stainless steel. 【Twist Drill】which makes the step drill bit less easily damaged than the ordinary step drill bit. Note: Oil the step drill bits before each use to maximize the service life. Twist Drill Bit 6542 is stronger than others High Quality The HSS hex shank drill is made of high quality hardened steel, not easy to damage With titanium coated to reduce friction and heat. Do not use center punch, compared to ordinary twist drill is not easy to break Double