求翻译：投标方应按有关国标或制造厂采用的标准选用材料，相关资料中要标出主要零部件材料牌号，当没有这些牌号时，应标明材料制造厂家，材料的物理特性、化学成分是什么意思？

Bidders should be adopted by the relevant national standard or factory standard selection of materials, related information that you want to mark the main spare part material grade, when no such brands is, manufacturers shall identify the materials, the physical properties of materials, chemical composition