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.Sirius 309 is a high-temperature stainless steel containing 23% Cr and 13% Ni. The alloy is a multipurpose high-temperature alloy.