... on both inside surface and outside surface.7.Superlow roughness on both inside surface and ... be traced in the record.Standard: DIN2391, EN10305-1, EN10305-3.Steel grade: ST35, ST37, ST45, ... ST52, E235, E355.Tube OD: 5-80mmTube WT: 1.5-8mmCondition: BK, BKW, BKS, NBK, GBK.Management ... transportation.EN10204/3.1 mill test certificate is sent together with goods. EN 10305-1 precision seamless steel ...