space204 2006-9-3 01:28
求助：surface finish N7
SURFACE FINISH N7 是一种什么处理？请各位大侠见教。
龙龙 2006-9-4 19:21
Grade Numbers Older drawings may use roughness grade numbers to indication Ra values. The following table is given in ISO 1320:1992. Roughness values Ra Roughness Grade Numbers micrometer microinches。