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 Type M42 is capable of being heat treated to Rockwell C 68-70; in fact, it is a super high-speed steel. Its combination of composition and properties makes it suitable for machining high-hardness alloys and difficult-to-machine superalloys. Excellent wear resistance and high hot hardness are obtained in Type M42 without loss of cuttting-edge toughness. Typical tools made from this steel are broaches, drills, gear cutters and milling cutters.