The prototype of the CR450 high-speed train – the world's fastest high-speed train – is undergoing type tests. The CR450 must decelerate from 400 kilometers per hour to a full stop in just 112 seconds over 6,500 meters. Achieving this requires an exceptionally reliable brake system, particularly the brake disc hub. The brake hub demanded a precision tolerance of just 0.005 millimeters – about one-sixteenth the thickness of a human hair. After months of research, the Chinese technical team not only cracked the challenge of machining the hub on a lathe, but also eliminated an entire production step and doubled efficiency compared to foreign grinding techniques. Source: CGTN Editor: Lyu Yun