Spiral grooved step drill bit, 4mm to 12mm, 1/4 inch M35 Cobalt shank, 9 sizes, multi-cone bits

Features: 1. Faster and Smoother Cutting: The four spiral flutes and cutting blades of this step drill bit ensure a faster and smoother cut, giving the impression of cutting through butter. 2. High Speed: Made with a high-speed design, this step drill bit is perfect for drilling stainless steel, sheet metal, wood, plastic, aluminum, copper, and other metal plates. 3. High Hardness: With a surface hardness of 89HRC, this step drill bit can cut through harder materials and achieve higher cutting speeds. 4. Material: The step drill bit is made of M35 cobalt steel, known for its excellent heat resistance, strength, and durability. 5. Diameters: Designed to drill nine different hole sizes ranging from 4 mm to 12 mm, and it features a 1/4-inch shank for easy compatibility with various drilling machines. Specifications: Item Type: Step Drill Bits Material: Cobalt M35 Hole Diameter: 4-5-6-7-8-9-10-11-12 mm / 0.2-0.3-0.4-0.5 inches Shank Diameter: 1/4 inch Package List: 1 x Step Drill Bit 1 x Storage Box