Aluminum Alloys, 2024-T2, -T3, -T4 
Index
The 2000 series of aluminum alloys have copper as the major alloying element, and the Tn designation is associated with the heat treatment. 

For the 2024 alloy, the nominal composition is 4.4%Cu, 0.6% Mn, 1.5% Mg, in an aluminum matrix. T2 signifies an alloy that has been cooled from the single phase condition to room temperature, cold worked, and naturally aged; T3 is an alloy of the same composition that has been furnace solution heat treated, quenched to room temperature, and cold worked; for the T4 alloy furnace solution heat treatment is followed by quenching and natural ageing.

For 2024-T3: UTS = 485 MPa, Tensile yield stress = 345MPa, 
Elongation in 50 mm = 18%

For 2024-T4: UTS = 470 MPa, Tensile yield stress = 325 MPa, 
Elongation in 50 mm = 20%