The Corrosion Rating Scale Guidelines contain corrosion rating scales, rating guidelines, and photographs for the determination of corrosion severity on all vehicular parts, including body and sheet metal, undervehicle and underhood components, and fasteners. It is intended that the scales are used for both corporate corrosion inspections and field surveys.

The purpose of the rating scale is to allow comparison between vehicles and consistency between personnel. It is important to recognize that rating corrosion involves perception of an objectionable surface and much of the judgement is subjective. In developing the corrosion scales, we have tried to provide some objective measure that will guide subjective judgement.