The NIST WWW Structural Ceramics Database (WebSCD) provides evaluated materials property data for a wide range of advanced ceramics known variously as structural ceramics, engineering ceramics, and fine ceramics. These materials tend to have low mass densities and high strengths and tend to be resistant to corrosion. These characteristics form the basis for applications of these materials in high-temperature, energy-efficient heat exchangers, advanced engine designs, bearings, wear resistant parts, and stable electronic substrates and electronic packaging.The range of materials covers the major series of compounds derived from the ceramic oxide, carbide, nitride, boride, and oxynitride chemical families. The materials are described by specification and characterization information that includes processing details and chemical compositions. Physical characteristics such as density and crystal structure are given in numeric tables. All measured values are evaluated and supported by descriptions of the measurement methods, procedures, and conditions. In all cases, the sources of the data are fully documented in a detailed bibliography.