... Q215, Q235, Q275, Q345, 20#, 45#, Stainless steel, Seamless steel, Alloy steel.3. SURFACE:Bared, Galvanized, Oiled, Color Paint ... road fence, traffic signs.(3).Construction engineering: steel structure construction, sports venue, three-dimensional garage, ... , tower crane.6. SPECIFICATION: SQUARE TUBE(MM) THICKNESS (MM)SQUARE TUBE (MM)THICKNESS(MM)15* ... solve your worries. High Quality Square steel pipe