自2012年1月起，本规范已被SAE航空航天材料部宣布“取消”，并被SAE AMS 4154取代。当参考已取消的AMS 4168时，应满足最新版SAE AMS 4154的要求。通过这一行动，本文件仍将列在航空航天材料规范索引的数字部分，并指出其已被SAE AMS 4154取代。本规范涵盖挤压棒材、棒材、线材、型材和管材形式的铝合金。 这些产品通常用于机械加工过程中易产生过度翘曲的零件，以及需要高强度且其制造不涉及焊接或成型的零件，但使用不限于此类应用。某些设计和加工程序可能会导致这些挤压件容易发生应力腐蚀开裂；SAE ARP 823建议尽量减少此类情况。

This specification has been declared "CANCELLED" by the Aerospace Materials Division, SAE, as of January 2012 and has been superseded by SAE AMS 4154. The requirements of the latest issue of SAE AMS 4154 shall be fulfilled whenever reference is made to the cancelled AMS 4168. 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will remain listed in the Numerical Section of the Index of Aerospace Materials Specifications, noting that it has been superseded by SAE AMS 4154.This specification covers an aluminum alloy in the form of extruded bars, rods, wire, profiles, and tubing.These products have been used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 subject to excessive warpage during machining and for parts requiring high strength and whose fabrication does not involve welding or forming, but usage is not limited to such applications.Certain design and processing procedures may cause these extrusions to become susceptible to stress-corrosion cracking; SAE ARP 823 recommends practices to minimize such conditions.