This specification has been declared "CANCELLED" by the Aerospace Materials Division, SAE, as of January 2012 and has been superseded by SAE AMS 4617. The requirements of the latest issue of SAE AMS 4617 shall be fulfilled whenever reference is made to the cancelled AMS 4166. By this action, this document will remain listed in the Numerical Section of the Index of Aerospace Materials Specifications, noting that it has been superseded by SAE AMS 4617.

This specification covers an aluminum alloy in the form of extruded bars, rods, wire, profiles, and tubing.

These products have been used typically for parts requiring high strength and resistance to stress-corrosion cracking, but usage is not limited to such applications.