The purpose of brake is to decelerate a vehicle by transforming the kinetic energy of the vehicle to heat via friction and dissipating that heat to the surroundings. As a part of an automobile, brake materials have additional requirements like resistance to corrosion, light weight, long life, low noise, stable friction, low wear rate and acceptable cost versus performance. Selection of the material is often based on experience or a trial and error method. This paper deals with the performance of a NAO(Non asbestos organic) disc brake friction material for a four wheeled vehicle. There are different friction performance properties such as base line check, average coefficient of friction. The physical properties are studied according to Indian standards. The results are discussed and correlated to the observed friction phenomenon.

Keywords: Coefficient of friction, speed, disc brake, NAO.