Brake lining by friction conversion car's kinetic energy into heat. Two brake pads are included in the brake caliper with their friction surface in the face of the rotor. When the brake hydraulic applications, caliper clamp or squeeze the two pieces together into a slow rotation of the rotor/stop the vehicle. When a brake pad is heated by contact with the rotor, it sends a small amount of friction material on the CD, the dark grey. Brake block and plate (both present and friction material), then the "sticky" to each other, to provide friction to stop the vehicle.
In the application of disc brakes, usually 2 per disc rotor brake pads, remain in place, and through a fixed to a hub or suspension column caliper actuators. Although almost all roads are only two vehicles each caliper brake pads, racing calipers use as many as six welding plate, with a crisscross pattern, in order to obtain the best performance change of the friction performance. According to the nature of the material, the disc wear rate may change. Brake block usually must be replaced periodically, depending on the cushion materials), and most are equipped with a warning drivers method if it needs to happen. With the center of a small groove, wear eventually disappear by indicating the pad close to its life end of manufacturing. Other adopt soft metal in a similar situation, when through exposure to braking scream aloud thin belt. Some people have a soft metal embedded in a closed circuit, and lit the dashboard warning lights, when the brake pads thin pad material.