Aluminum Rectangular Tube, Aluminum, 6061, T6, Rectangular, 6 in Overall Length, 3 1/2 in Inside Width, 1 1/2 in Inside Height, 4 in Outside Width, 2 in Outside Height, 0.25 in Wall Thickness, Wall Thickness Tolerance +/-0.011 in, Fabrication Extruded, Heat Treatment Tempered, Heat Treatable Heat Treatable, Mechanical Finish Mill, Yield Strength 40,000 psi, Tensile Strength 45,000 psi, 95 BHN Brinell Hardness, 60 HRB Rockwell Hardness