... ,GB/T3091-2001,GB/T13793-92, GB/T6728-2002MaterialsQ195,Q235,Q345,A36,SS400,ST37-2Product CategoryMetallurgy, Mineral & EnergyTechniqueWeldedPacking1.Big OD: in ... -635-2128822 Fax:86-635-2128822Mobile phone:86-15954587083Skype:cherryhuang880104 hot dipped galvanized steel square tube