This Databook of engineering properties of ceramics supersedes the Materials Selection Handbook, issued in October, 1963, as RTD-TDR-63-4102 and its two supplements dated May 1964, and April 1965. The materials covered are principally refractory inorganic compounds in the form of monophase crystalline ceramics. Exceptions are the coverage of selected refractory composite materials and intermetallic compounds, as well as metalloid elements of boron, silicon, and germanium. Excluded are glasses, carbons, graphites, and compounds melting below about 2000 F (1200 C). Properties given are those pertinent to structural engineering. The data are in a format designed to permit comparison and selection of materials as well as to provide details on each specific material. Discussions of factors affecting property values and structural application of brittle materials also are included.