The Refractory Carbides is intended as a guide to the chemist who wishes to undertake a fundamental study of refractory carbide systems. No effort has been made to discuss all of the properties for which information is available. Rather, the selection is intended to give the reader information and some insights which are basic to any measurement. This work includes a number of the more important physical and chemical properties of the nine transition elements included in Groups 4, 5, and 6 of the 4th, 5th, and 6th periods. The three actinide systems, Th-C, U-C, and Pu-C, have also been discussed. While this limited selection does not include all of the high melting carbides, it does include the more refractory and the more useful ones. These systems offer a unique collection of properties for an understanding of the chemical bond. Each system is discussed individually in terms of each property. These include phase relationship, lattice parameter and structure, chemical stability, hardness, and thermochemical properties which include vaporization behavior. In addition, the thermal data for the carbides and many of the associated elements have been reevaluated.