Free Engineering Information Resources

ChemSpider is a free chemical structure database providing fast access to over 120 million structures, along with properties and associated information. By integrating and linking compounds from hundreds of high quality data sources, ChemSpider enables researchers to discover the most comprehensive view of freely available chemical data from a single online search.

Includes a database of material property data sheets covering plastics, metals, ceramics and other engineering materials. The web site can be used freely without registration but users are required to register to use the advanced features. There is a charge to use some of the advanced features.

The free Standard Reference Data catalog provides access to dozens of databases that are free to search. These databases cover a wide range of substances and properties. Some of the databases included are the NIST Structural Ceramics Database, the NIST High Temp. Superconducting Materials Database, the NIST Chemistry WebBook, and the CODATA Fundamental Physical Constants.

PubChem is an open chemistry database at the National Institutes of Health (NIH). “Open” means that you can put your scientific data in PubChem and that others may use it. PubChem mostly contains small molecules, but also larger molecules such as nucleotides, carbohydrates, lipids, peptides, and chemically-modified macromolecules. We collect information on chemical structures, identifiers, chemical and physical properties, biological activities, patents, health, safety, toxicity data, and many others.

SDBS is an integrated spectral database system for organic compounds, including 6 different types of spectra under a directory. It's organized by the National Institute of Advanced Industrial Science & Technology (AIST) in Japan.