1) Co:10-12% 2) Grain size: 0.5-0.6um 3) DIN or ANSI standard 4) ISO9001:2000 5) Coated or not coated polishing carbide drill (with straight shank)Diameter: 1mm-30mm Coated: Tialn, tin (option)casting iron,aluminium process We supply you various drill bit, solid carbide drills, cemented carbide drills including step drill, twist dirlls, center drills, drills with straight flute, suitable for high ...