SUPERSEDING SPECIFICATION: The requirements of this specification are embodied in the latest issue of AMS 4118, ALUMINUM ALLOY BARS, ROLLED OR COLD FINISHED, 4.0Cu - 0.70Mn - 0.60Mg - 0.50Si (2017; -T4, -T451), Solution Heat Treated. The requirements of the latest issue of AMS 4118 shall be fulfilled whenever reference is made to this specification.