This specification has been declared "CANCELLED" by the Aerospace Materials Division, SAE as of January 2009 and has been superseded by AMS 2644. The requirements of the latest issue of AMS 2644 shall be fulfilled whenever reference is made to the cancelled AMS 3157. By this action, this document will remain listed in the Numerical Section of the Index of Aerospace Material Specifications, noting that it is superseded by AMS 2644.