Disc Brake System: Specifications

Diameter 245.0 mm (9.65 in)
New Thickness (Nominal) 11.0 mm (0.44 in)
Minimum Thickness After Refinish 9.3 mm (0.37 in)
Discard Thickness 9.0 mm (0.35 in)

Brake Drums and rotors have a discard diameter or thickness cast into them. This a wear dimension and not a refinish dimension. Any drum or rotor which does not meet the specification should be discarded.