China's Five-hundred-meter Aperture Spherical Telescope (FAST) is undergoing a significant upgrade as it replaces its six imported steel support cables for the feed cabin with domestically manufactured alternatives. These six cables, each weighing over six tonnes and totaling nearly 4,000 meters in length, are crucial for the precise real-time positioning of the 30-metric-ton feed cabin within a 140-meter altitude and a 206-meter range. The extensive replacement process is scheduled to conclude by late June. The development of these domestic cables, initiated in 2023, involved rigorous testing, including tens of thousands of sliding cycles and pulse fatigue tests, culminating in successful trials by August 2025. This transition aims to reduce import dependency and showcases China's advancements in materials science and engineering.