... Certification:API 3.Professional manufacturer ASTM A106 GR.B Carbon Steel Pipe product name-main material- ... 3Cr13(420)GB/T 14976-2002GB/T 14975-2002 -Decorative Stainless Steel 4-426×1-40 ... -40 Rectangular TubeQ195,Q235,Q345,20#GB/T6278-2002 Structure, decoration, construction20*20-500*500 ductile ... Q345,20#GB/T6278-2002 Structure, decoration, construction20*20-500*500ASTM A53 GR.B Carbon Steel Pipe in ...