The document discusses the material properties of aluminum alloys 6063-T4 and 6063-T5. 6063-T4 has an ultimate tensile strength of 19,000 psi up to 0.5 inches thick and 18,000 psi from 0.5 to 1 inch thick, with a yield strength of 10,000 psi up to 0.5 inches and 9,000 psi from 0.5 to 1 inch. Its elongation is 14%. 6063-T5 has higher strength levels and lower elongation, with various strength specifications provided for different thickness ranges. Chemical composition of the 6063 alloy is also listed, with aluminum as the primary constituent along with controlled amounts of silicon, iron, copper, manganese,