In aluminum alloy designations, which number indicates the metal has received no hardening or tempering treatment?

In aluminum alloy designations, the letter 'F' in the designation refers to a 'As Fabricated' condition, meaning that the alloy has not undergone any heat treatment or specific hardening processes. The number '3003' indicates that it is a non-heat-treatable alloy, and the 'F' signifies that it is in its natural state after fabrication.

Although other designations like 'T' indicate that the alloy has undergone some form of thermal treatment to enhance its mechanical properties, the presence of 'F' clearly denotes the absence of such treatments. Therefore, the designation '3003-F' unambiguously states that the alloy has not received any hardening or tempering treatment.