SUTTON TOOLS® D108-Series Heavy Duty Cobalt Jobber Drill Bits are an industrial quality drilling solution for drilling materials that have high hardness and tensile strength such as cast iron, bronze, hardened steel and stainless steel. These bits feature a thick core for increased rigidity when drilling hard metals. Features 135° Split Point - Enables accurate positioning and less drilling pressure, Thick Core - For increase rigidity in hard materials, Precision Engineered Parallel Shank - For accurate hole size, Made from HSS-Co - The 5% cobalt formula improves abrasive and heat resistance, for increased strength at higher cutting temperatures, Colour Tempered Surface Finish - Enables identification of cobalt tool material, Specifications Diameter: 8.0 mm, Working Length: 75 mm, Overall Length: 117 mm, Point Angle: 135°, Helix Angle: R30, Point Tolerance: h8, Point Form: Form c, Material: HSS-Cobalt, Finish: Colour Temp,