The thermal expansion of the brake disc along the thickness direction is very small, which will not increase the brake clearance significantly as the brake drum does, resulting in excessive brake pedal travel; It is easy to realize automatic clearance adjustment, and other maintenance and repair operations are relatively simple.

The brake disc is the friction coupling part of the disc brake. In addition to the strength and stiffness required as a component, it should also have a high and stable friction coefficient as much as possible, as well as appropriate wear resistance, heat resistance, heat dissipation and heat capacity. The brake disc (or rotor) is a rotating part of the wheel disc brake assembly, on which the brake pads rest. The material is usually gray cast iron, a kind of cast iron.