Rotor Tolerance & Surface Finish

Tolerances of the braking surfaces for flatness, parallelism and lateral runout are closely held. The maintenance of close tolerances on the shape of the breaking surfaces is necessary to prevent brake roughness or pulsation. The surface finish must be held to a specific range of 60 Ra roughness or less. The control of the surface can improve lining life. Light scoring of the rotor surfaces not exceeding 1.5 mm (0.06 in.) in depth is normal and not detrimental to brake operation.