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.Phytherm 55 is a 30 nickel balance iron alloy, and Phytherm 120 is a 30Ni-3Cu-2Cr-balance iron alloy. Both are soft magnetic alloys.