Aluminum Square Tube, Aluminum, 6063, T52, Square, 36 in Overall Length, 2 1/2 in Inside Width, 2 1/2 in Inside Height, 3 in Outside Width, 3 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 21,000 psi, Tensile Strength 27,000 psi, 60 BHN Brinell Hardness, 17 HRB Rockwell Hardness, Includes Material Certificate Material Certificate with Lot Number