Specific gravity is a nondestructive test used as a quality control check of the consistency of formulation and processing of brake lining. Specific gravity alone shows nothing about a lining's ability to develop friction or to resist fade when used as a friction element in brakes. Specific gravity varies with the formulation of the lining. The specific gravity of sintered metal powder linings@ particularly those which have steel backing members@ is usually determined somewhat differently. Reference ASTM B 376@ ??Density of Sintered Metal Friction Material' peculiar to each formulation and@ therefore@ the acceptable values or range must be established for each formulation by the manufacturer. Purpose To establish a uniform procedure for determining the specific gravity of brake lining.
SAE J380-1969 history
2017SAE J380-2017 Specific Gravity of Friction Material
2009SAE J380-2009 Specific Gravity of Friction Material
2002SAE J380-2002 (R) Specific Gravity of Friction Material