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.Invar M93T is the filler metal developed for the welding of Invar M93 tubes by plasma arc welding (PAW) or gas tungsten arc welding (GTAW).