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.ALUMINUM 2018 is an age-hardenable aluminum forging alloy characterized by relatively high tensile and yield strengths along with fairly good ductility. It has good elevated-temperature properties. Its applications include engine pistons and engine cylinder heads.