View Sample Alloy Digest Data Sheet (PDF)Since 1952, Alloy Digest has been the leading reference for materials property data on metals and alloys used throughout the world. Featuring graphs, charts and tables, these sheets give facts and figures on composition or characterization, physical and mechanical properties, heat treatment, and machinability.The aluminum-lithium alloy 2099, also designated C460, was developed for use in aerospace and high-strength applications. The alloy has a lithium addition for lowered density compared to more conventional alloys.