ISO 4521:2008规定了电气、电子和其他工程应用的电镀银和银合金涂层的要求，包括试验方法。工程应用是指涂层基本上用于非装饰目的的应用。 尽管ISO 4521:2008未规定电镀前基材的条件、光洁度或表面粗糙度，但电镀银和银合金涂层的外观和可用性取决于基材的条件。 买方必须规定基材的表面光洁度和粗糙度，以符合产品要求。 ISO 4521:2008不适用于螺纹上的涂层，也不适用于非制造形式的薄板、带材或线材上的涂层。

ISO 4521:2008 specifies requirements for electroplated silver and silver alloy coatings for electrical, electronic and other engineering applications, including test methods. Engineering applications are defined as those in which the coating essentially serves a non-decorative purpose. Although ISO 4521:2008 does not specify the condition, finish or surface roughness of the basis material prior to electroplating, the appearance and serviceability of electroplated silver and silver alloy coatings depends on the condition of the basis material. It is essential that the purchaser specifies the surface finish and roughness of the basis material in order to conform to the product requirements. ISO 4521:2008 does not apply to coatings on screw threads or to coatings on sheet, strip or wire in the non-fabricated form.