In manufacturing the brake rotor, tolerances of the braking surfaces are closely
held for the following conditions:
The maintenance of close tolerances on the shape of the braking surfaces
is necessary in order to prevent brake roughness or pulsation.
In addition to these tolerances, the surface finish must be held to a specific
range. This range is 60 Ra roughness or less. The control of the braking surface
finish is necessary in order to avoid the following problems:
Control of the surface finish may improve the lining life. Light scoring of
the rotor surfaces not exceeding 1.5 mm (0.059 in) in depth,
which may result from normal use, is not detrimental to brake operation.