1.1 本规范涵盖了金属制品上电沉积（电镀）锡涂层的要求。锡涂层用于提供低接触电阻表面，以防止腐蚀（参见 1.2 )，以便于焊接，提供抗磨损性能，并在高强度钢的氮化过程中作为阻挡涂层。 1.2 暴露在室外的锡涂层可能会产生一些腐蚀。在正常的室内暴露条件下，锡对铁、钢、镍、铜及其合金具有保护作用。由于锡和下层金属之间通过不连续处形成电偶，特别是在潮湿的环境中，涂层中的不连续处（如孔隙）可能会发生腐蚀。孔隙率随着涂层厚度的减小而增加，因此必须为每个应用指定最小厚度。 涂有锡的零件可在与钢铁、涂锡铝、黄色镀铬锌、镉和焊料涂层接触的情况下安全组装。（参见 第5.1节 氧化和腐蚀性能。） 1.3 本规范适用于不低于99 % 锡（除非为特殊目的而特意合金化，如 X6.3英寸 )从任何可用的锡电镀工艺中获得（参见 4.3 ). 1.4 本规范不适用于热浸镀锌或其他非电沉积涂层；它也不适用于工厂产品。有关磨机产品，请参阅规范 第623页 或 623米 . 1.5 单位- 以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。

1.1 This specification covers the requirements for electrodeposited (electroplated) coatings of tin applied to metallic articles. Tin coatings are used to provide a low contact-resistance surface, to protect against corrosion (see 1.2 ), to facilitate soldering, to provide anti-galling properties, and to be a stopoff coating in the nitriding of high-strength steels. 1.2 Some corrosion can be expected from tin coatings exposed outdoors. In normal indoor exposure, tin is protective on iron, steel, nickel, copper, and their alloys. Corrosion can be expected at discontinuities in the coating (such as pores) due to galvanic couples formed between the tin and the underlying metal through the discontinuities, especially in humid atmospheres. Porosity increases as the coating thickness decreases, so that minimum thicknesses must be specified for each application. Parts coated with tin can be assembled safely in contact with iron and steel, tin-coated aluminum, yellow chromated zinc, cadmium, and solder coatings. (See X5.1 for oxidation and corrosion properties.) 1.3 This specification applies to electroplated coatings of not less than 99 % tin (except where deliberately alloyed for special purposes, as stated in X6.3 ) obtained from any of the available tin electroplating processes (see 4.3 ). 1.4 This specification does not apply to hot-dipped tin or other non-electrodeposited coating; it also does not apply to mill products. For mill products, refer to Specifications A623 or A623M . 1.5 Units— The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.