... thickness1.8mm-30mmstandardAPI5L,API5CT,ASTM-A106,ASTM-A53,SY5037-2000,GB/T5711.1-1997MaterialX42,X52,X60,X65,X70,Q235,Q345,10#,20 ... 53-2007DIN : DIN EN 10216-1-2004 / DIN 1630API : API 5CT / API 5L / API5DPGB : GB /T 9711.1-1997 GB /T 9711.3-2005 ... GB /T 8163Material 20# 45#API J 55 ...