159无缝钢管国标厚度

2252833235445555665775825壁厚0405060811214151618222252833235445555665参考资料国家标准,GB#47T81621999,结构用无缝钢管。DN40ф45mmDN50ф57mmDN65ф73mmDN80ф89mmDN100ф108mmDN125...