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.AK Steel 439 Ultra Form (UF) has oxidation resistance and corrosion resistance superior to Type 409. The alloy also has an equiaxed microstructure and improved formability.