... A 53 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless2. GB/T8162 Seamless Steel ... general structural purposes5.DIN 2448 SEAMLESS STEEL PIPES AND TUBES6.EN 10210 Seamless structural steel pipes Steel ... , Blow Test, Impact Test etc), Exterior Size InspectionUsageApplicable to the general structure, mechanical structure with seamless steel tubes stainless ...