ASTM B700-20 

This specification establishes the requirements for electrodeposited silver coatings that may be mat, bright, or semibright, and are usually employed as solderable surfaces and for their electrical contact characteristics, high electrical and thermal conductivity, thermocompression bonding, wear resistance on load-bearing surfaces, and spectral reflectivity. Coatings shall be classified into types according to minimum purity, grade according to surface appearance (bright, semibright, or mat), and class according to whether any surface treatment has been applied. Coatings shall undergo preplating operations such as stress relief treatment, strike, and underplating, as well as post-plating embrittlement relief. Coatings shall be sampled, tested, and conform accordingly to specified requirements as to nature, purity, appearance, defects, adhesion, solderability, hardness, spectral reflectance, electrical conductivity, hydrogen embrittlement relief, and thickness (measured either nondestructively by beta backscatter, X-ray spectrometry, or magnetic method, or destructively by coulometric technique or microscopical cross-sectioning procedure).