Ideal for home DIY projects, building tasks and engineering use. HSS drill bits diameters: 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm. Drill bits set mainly for drilling wood, plastic, fiberglass, printed circuit boards (PCB), and metal including copper, aluminum, tool steel, cast iron, and heavyduty abrasive alloy metal. HSS drill bits set speed steel with coating treatment, tougher and more abrasion resistant. Key benefits Versatile size range supports precise work across many small drilling tasks. Suitable for multiple materials including wood, plastic, fiberglass, PCB and various metals. Coated speed steel provides increased toughness and abrasion resistance for longer life. Use scenarios Woodworking and home improvement: drilling pilot holes and small holes in soft and hardwoods for furniture and fixtures. Electronics and plastics: drilling PCB holes and plastic component fits with consistent accuracy. Metalworking: drilling copper, aluminum, tool steel, cast iron, and other heavyduty alloys with reliable performance.