... 4) Material: hot dip square steel pipe 1.size:10*10mm-600*600mm2.thickness:0.5mm-60mm4.Satndard: BS1387,EN10219,ASTM A53, ASTM A363 ... .8m4. High Quality: ISO900:2000, API5L, API5CL Product square steel pipesStandardGB/T3091-2001,BS1387,ASTM A53, ASTM A106, EN10219MaterialQ195,Q215,Q235,Q345, 20 ...