Square steel pipe 10#,20#,45#,16Mn, ASTM A106 Gr.B, ASTM A53 Gr.B, St 37, St 42, ... specific inquiry will be highly appreciated! China GBASTMDIN 1717510#ASTM A106 Gr.AASTM A53 Gr.AASTM A179-CASTM A214-CASTM A192 ... St 37-2St 35.8St 35.420#ASTM A106 Gr.BASTM A53 Gr.BASTM A315 Gr.BASTM A210-A ...