Features Premium Quality: These step drill bits are made of high-strength steel with titanium coating, enabling efficient drilling in steel, aluminum, brass, copper, plastic, and wood. Various Sizes: This set includes three step drill bits with size ranges of 4–12 mm, 4–20 mm, and 4–32 mm to accommodate diverse drilling requirements. Application: Ideal for drilling holes in thin materials such as sheet metal, aluminum sheets, insulation panels, PVC panels, and wood up to 5 mm thick. Package Content: 1 x 4–12 mm step drill bit, 1 x 4–20 mm step drill bit, 1 x 4–32 mm step drill bit. Note: Actual color may vary slightly from images due to lighting conditions. Slight measurement variations of 1–3 cm may occur due to manual measurement. Material: High-speed steel with titanium nitride coating. Package List: 3 pcs step drill bits (4–12 mm, 4–20 mm, 4–32 mm).