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.ACI TYPE HX is a nickel-base austenitic casting, similar to HW (See Alloy Digest Ni-449), but containing more nickel and chromium, thus having better oxidation resistance. It is used in applications up to 1150 C (2100 F).