The handbook is becoming a standard reference for material property design infomation and is currently being used to support the design of the United States' Compact Ignition Tokamak (CIT). The handbook has evolved into two volumes. Volume 1, Engineering Design Data, is intended for use by designers, structural analysts, and material scientists who participate in reactor design studies. It contains engineering curves of data, extrapolations of the data, comparison of properties of various materials, information with regard to the treatment of data and recommendations as to the application of these materials and their operational limitations. Volume 2, Supporting Documentation, is essentially a material property data base, intended for use by the material scientists or researcher.It contains the actual experimental data used to develop the data curves, catalogues the data source, and discusses the relevance of the data sets and analysis procedures.