Drag chains and protective covers are widely used in CNC machine tools, electronic equipment, stone-processing machinery, glass-processing machinery, door-and-window manufacturing equipment, injection molding machines, robotic arms, lifting and conveying equipment, automated warehouses, medical devices, automation systems, robots, laser cutting, flame cutting, and other applications. The structure of a drag chain resembles a tank track, consisting of numerous modular links that rotate freely relative to one another. Drag chains within the same series share the same internal height, external height, and pitch, while the internal height and bending radius R can be selected from different options. Each modular link comprises left and right side plates as well as upper and lower cover plates; moreover, every link can be opened for easy assembly and disassembly, eliminating the need to thread cables through the chain—simply open the cover plate to insert cables, hydraulic hoses, pneumatic lines, and other components directly into the drag chain.