... 4.Steel Grade: Q235A, Q235B, Q345API 5L: GR A, GR B, X42,X46, X56, X60,X65,X70, X80ASTM A252 GR 1 ... , GR 2, GR 3ASTM A53: GR A, GR B, GR C, GR DBS 4360: Grade 43, Grade 50EN: S275 ... ur reply!Linda YuanSKYPE: lindayuan1124Mobile: +86-15226605670 SSAW Round Hollow Section Steel Tube with Fusion Bond Epoxy Coating