This SAE Recommended Practice provides the method to assign numerical values of brake effectiveness, using data from single station inertia dynamometer effectiveness tests, and to identify a uniform procedure to mark these values on the edge of brake blocks in excess of 12.7 mm (0.51 in) in thickness. The edge markings are intended to provide relevant and meaningful data on the normal and hot effectiveness of brake blocks, using the reference full size brake assembly, to aid in the characterization of these brake block frictional properties. This edge marking methodology is intended to permit accurate identification of the effectiveness values over the full wear life of the brake block. This is accomplished by means of permanent markings on one edge of the brake block.