Lee, S., Kim, S., Kim, S., and Rhee, S., "Brake Disc Variability: Effect on Friction and Wear," SAE Int. J. Passeng. Cars - Mech. Syst. 6(3):1455-1464, 2013, doi:10.4271/2013-01-2053.
Two sets of OE quality brake discs were evaluated for their equivalence in friction and wear under a humidity controlled condition in order to avoid the influence of humidity on friction and wear. These discs were received from two different suppliers located in two different countries. Small differences were found in disc chemistry and microstructure, which resulted in differences in disc properties, and friction and wear characteristics. It is recommended that extreme care must be exercised in determining the performance equivalence of one disc from one supplier against another disc from a second supplier.