SAE J 400

This SAE Recommended Practice covers a laboratory procedure for testing and evaluating the resistance of surface coatings to chipping by gravel impact. The test is designed to reproduce the effect of gravel striking exposed paint or coated surfaces of an automobile and has been correlated with actual field results. The specific intent of the test is to evaluate organic surface coatings or systems on flat test panels; however, it may be possible to extend this type of testing to finished parts or other types of materials such as anodized aluminum or plated plastics if the results are interpreted with respect to the limitations and intent implied by the original testing procedure and rating system.