Specular Ripostes of pure tin containing very small quantities of organic material.
Tin is remarkably resistant to corrosion under atmospheric condition.
Soft plates on a harder substrate give almost complete true contact resulting in a gastight, corrosion-resistant interface. A soft base metal plate with a thin, brittle surface corrosion film that can be easily penetrated mechanically is desired. Soft, pure tin develops thin, brittle, self-limiting corrosion films, and its theoretical constriction resistance ranks close to gold. Does not have as low a value of contact resistance as zinc, cadmium or gold, but in adequate thicknesses may retain a low value for a longer period of time. Bright tin, due to greater hardness and wear resistance, is preferred for such service.