HSS Step Drill Bit - Our step drill bit is primarily for drilling wood and steel, including metals, aluminum, wood, plastics, etc. Superior Material - Titanium-coated 4241 (HSS) high-speed steel reduces friction. It is more durable than uncoated drill bits, and HSS (high-speed steel) has a long service life. Multi-Purpose - Depending on the need to drill different diameter holes, there's no need to change the drill bit or reposition the hole. The double cutting blade design allows for faster cutting, and the hole is automatically deburred during drilling. Application - Precision 4mm holes can be drilled into 32mm holes of various sizes. Suitable For - Drilling tools, bench drills. Working with water cooling can effectively extend the drill bit's lifespan. Features: This drill bit is made from high-quality HSS steel and titanium-coated to reduce friction and heat. Suitable for drilling holes in a variety of materials, including steel, brass, wood, plastic, etc. No pilot holes or