... to 300 x 500mm Square Steel Pipe Wall thickness: 0.4 to 14mm Square Steel Pipe coating: Hot dip galvanized coating, ... black paint, clear oil. Square Steel Pipe Packing: Labeled and bundled together with steel strip Square Steel ... Pipe Steel grade: A, B, Q195, Q235, Q345, 16Mn and 15CrMo Square Steel Pipe Application: Structure steel pipe for furniture, door, window, frame. ...