Steel rail is the main component of railway track. Its function is to guide the wheels of rolling stock to move forward, bear the huge pressure of the wheels, and transmit it to the sleepers. The rail must provide a continuous, smooth and least resistance rolling surface for the wheels.
Steel rails must provide continuous, smooth and minimal rolling surfaces for train wheels. In electrified railways or automatic block sections, steel rails can also be used as railway lines. Steel rails must be able to withstand the working pressure and impact load of locomotives and vehicles.