Carbon Steel Square Tube, Material Carbon Steel, Material Grade A513, Inside Height 3 1/2 in, Inside Width 3 1/2 in, Outside Height 4 in, Outside Width 4 in, Overall Length 24 in, Fabrication Hot Rolled, Mechanical Finish Mill, Wall Thickness 0.25 in, Heat Treatable Heat Treatable, Heat Treatment No Heat Treatment, Yield Strength 55,000 psi, Rockwell Hardness Not Rated, Tensile Strength 65,000 psi, Machinability 100 Percent, Shape Square, Standards ASTM A500/A513, System of Measurement Inch