... °c.3.AlTiN-S coating, golden coating, applicative to high speed machine. Machine rotate speed is 8000rpm~20,000rpm, heat resistance is 1000°c~1200 ... resistance: The small grain size and the higher Co, the better wear-resistance.6.ZHY-600 series drill bit, grain size 0 ... 4um, Co12%, HRC60, AlTiN coating, Kennametal material, for high speed cutting.7.ZHY-650 series drill bit, grain size 0.2um, Co9%, HRC65 ...