gold alloy covering meaning in English

金合金表壳覆层

Gold alloy coverings on watch cases ; requirements , testing and marking
手表壳镀金层.要求试验和标记
Watch - cases and accessories - gold alloy coverings - general requirements
表壳和附件.金合金覆盖层.第1部分:一般要求
Horology . general requirements for gold alloy coverings on watch cases and horological components
钟表业.表壳和钟表零件金合金镀层的一般要求
Watch - cases and accessories - gold alloy coverings - determination of fineness , thickness , corrosion resistance and adhesion
表壳和附件.金合金覆盖层.纯度厚度耐腐蚀性能和结合强度的测定