Features: 1. Solid carbide tools offer long tool life and faster cutting speeds than other substrates and must be used with rigid tool holding systems. 2. Cobalt titanium coatings add a hard layer of gold-colored ceramic to the surface that extends tool life and has faster-cutting speeds than uncoated tools. 3. High-strength material M35, 90° chamfer, higher hardness, and stable performances. Using this 90 degree location center bit, positioning and chamfering are completed at the same time. 4. Fully ground spiral groove design clears particles quickly, and decreases friction and heat for faster, faster cooling drilling performances. 5. Fit for stainless steel, alloy steel, hardened and tempered steel, cast iron, aluminium alloy, and spring steel. Specification: Material: M35 Color: Gold & Silver Product Size: Diameter x Sharpblade Length x Overall Length: 3 x 17 x 50mm, 4 x 20 x 55mm, 5 x 23 x 60mm, 6 x 25 x 65mm, 8 x 30 x 80mm, 10 x 35 x 90mm Product Weight: 30g, 40g, 50g, 60g, 70g, 80g Package Included: 1 x 90 Degree Center Drill Bit