Engineering handbooks are reference resources created exclusively for engineers. Such materials often include indexes and other applied engineering materials. Handbooks tend are very technical.
ASM Handbooks Online - The American Society for Metals (ASM) Handbooks feature the complete content of thirty ASM volumes, several ASM Handbook supplements, and two ASM Desk Editions
CRC Handbook of Chemistry and Physics - Originally standing for the Chemical Rubber Company, these resources provide an in-depth coverage regarding the properties of inorganic and organic compounds.
The Electrical Engineering Handbook - Written by Wai-Kai Chen and part of the Safari Tech Books online collection (see Safari link below). Provides resources for electrical engineers and engineering students.
Perry’s Chemical Engineer’s Handbook - An excellent source for chemical engineering information and data.
Safari Tech Books - Offers a wide range of materials including technical materials in the disciplines of engineering and the physical sciences.