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.AISI 4340 steel is a tough, shock resisting, oil hardening nickel-chromium-molybdenum steel. In the heat treated condition it has the highest combination of tensile and endurance strengths along with ductility.