motion is converted into waste heat which must be dispersed. Disc brakes are commonly used for vehicle braking but they are applicable to almost any rotating shaft. The brake disc (or rotor in American English) is usually made of cast iron, but in some cases it is made of composites such as reinforced carbon or ceramic matrix composite materials. It is connected to the wheel or to the axle. Brake pads are the friction material, mounted on a device called a brake caliper, is forced mechanically, hydraulically