... Q215, Q235, Q275, Q345, 20#, 45#, Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color Paint, 3PE; Or ... , container, tricycle, tower crane.6. SPECIFICATION: SQUARE TUBE(MM) THICKNESS (MM)SQUARE TUBE (MM)THICKNESS(MM)20*301.5-3.2590 ... this area.We engaged in research square and rectangular steel tube at the beginning of company established, now our technology ...