When sourcing 6061 aluminum plates, you must prioritize the T6 temper condition, which indicates the material has been solution heat-treated and artificially aged for maximum tensile strength. Ensure the chemical composition adheres to ASTM B209 or EN 485 standards, specifically maintaining magnesium and silicon levels to guarantee excellent weldability and corrosion resistance. For precision applications, verify that the thickness tolerance meets your specific engineering requirements, as standard commercial tolerances may vary.