【High-quality Material】: Pro Edge Technology 1pc Cobalt Step Drill Bit made of harder and more wear-resistant M35 cobalt high-speed steel, it has excellent hardness, and can easily and quickly drill holes in stainless steel plates, cast iron plates, copper plates and aluminum plates, and is also suitable for wood and plastic. 【Four-Flute Spiral Groove】: The four spiral groove design can make chip discharge smoother, the cutting force distribution more even, reduce the risk of blockage, improve the efficiency of drilling, reduce vibration and ensure stability. 【Nano-Grade Industrial TiAlN Coating】: Pro Edge Technology step drill bit use industrial-grade TiAlN coating, which increases the hardness to 90HRC, can withstand high temperatures, minimize drill wear, and extend the service life of the step drill by 3-5 times. (The service life of cobalt step drills with TiAlN coating is more than 10 times that of ordinary M2 HSS drills.) 【12 Sizes in 1 and Hex Shank】: Our 1-piece cobalt step drill bit comes with 12 sizes to meet most drilling needs. Sizes includes 12 sizes: 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8". The hexagonal shank enhances clamping stability, is easy to replace, and is compatible with most chucks on the market. 【Service Guarantee】: We are committed to providing high-quality products and services. For any feedback or dissatisfaction with our products, please contact us promptly. We are happy to assist you.

A 3/16"-7/8" M35 step drill bit includes 12 sizes: 3/16", 1/4", 5/16", 3/8", 1/2", 9/16", 5/8", 11/16", 13/16", and 7/8". Shank type: Hex Shank. Coating type: Industrial TiAlN. Four-Flute Spiral Groove. Can be used forstainless steel plates, cast iron plates, copper plates, and aluminum plates, while also being suitable for wood and plastic.