Product Code:SAE J380 Title:Specific Gravity of Friction Material Issuing Committee:Brake Linings Standards Committee Scope:Specific gravity is a nondestructive test used as a quality control check of the consistency of formulation and processing of brake lining. The specific gravity and the range of specific gravity are peculiar to each formulation and, therefore, the acceptable values or range must be established for each formulation by the manufacturer. Specific gravity alone shows nothing about a materials in use performance. The specific gravity of sintered metal powder friction materials, particularly those which have steel backing members, is usually determined somewhat differently. Reference ASTM B 376.PurposeTo establish a uniform procedure for determining the specific gravity of brake friction material.