MatWeb

A free online materials information resource with properties data on over 28,000 materials. Search for materials by name or properties. Database includes comprehensive coverage of thermoplastic and thermoset polymers, aluminum, cobalt, copper, lead, magnesium, nickel, steel, superalloys, titanium and zinc alloys, ceramics, plus a growing list of semiconductors, fibers, and other engineering materials. Advanced features for registered and premium users.