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.NITREX-I is a special alloy steel that can be surface hardened by the nitriding process. Vacuum consumable remelting renders the alloy exceptionally uniform and free from impurities.