1.1 ,This practice covers the testing of the James Machine for repeatability of static coefficient of friction, relative to a standard reference interface consisting of the working surfaces of Borco2 board and standard leather shoe sole material, or a control polish film and standard leather shoe material. The practice provides basis data on the stability of the James Machine to ensure accurate static coefficient of friction determinations over time and repeated use and for determining if the James Machine is mechanically calibrated and properly aligned.