http://www.howardprecision.com/an-in-depth-look-at-2024-aluminum-from-howard-precision - Alloy 2024 was introduced by Alcoa in 1931. Alloy 2024 is available in plate from .250 through 6.00" thicknesses in a T351 temper. Alloy 2024 is used in a variety of applications such as fuselage structural, wing tension members, hydraulic manifolds, shear webs and ribs, and structural areas where stiffness, fatigue performance, and good strength are required.