... 6-25mmRectangle Pipe20*30 - 400*600mm0.6-25mmDetail information:MaterialQ195, Q215,Q235, Q345SurfaceTreatmentBlack rust-proof oil, transparent oil, Zinc coatedThickness Tolerance± ... pipes :Low Pressure Fluid Transmission Pipe:GB/T 3091 Q195,Q215,Q235, Q295, Q345, 10#,20#, 16Mn etc.GB/T 13793 ... steel pipe Erw Round Structural steel pipesGB/T 13793 Q195,Q215,Q235, Q295, Q345, 10#,20#, 16Mn etcEN 10219-2 ...