Sources for engineering data on parts and materials.
Michael Ashby presents materials information in a practical format in his book Materials Selection in Mechanical Design.
Materials Selection in Mechanical Design
This is a link to lecture notes that give an idea of his approach:
http://www.uofaweb.ualberta.ca/cme/pdfs/443ashbylectures2006.pdf
ThomasNet provides a link to a useful white paper on Timing Belt Theory by Gates-Mectrol:
http://www.thomasnet.com/white-papers/abstract/101106/timing-belt-theory.html
Geometric data on timing belt drives can found in the catalog linked to Gates-Mectrol home page:
Gear geometry data is available from PIC Design Inc. which is now part of RBC Bearings at the link:
http://www.pic-design.com/static/PDF/Catalog%2045.0.pdf
RBC Bearings Logo
Stock Drive Products provides an on-line Handbook of Gears at the website:
http://www.sdp-si.com/D190/D190cat.htm
Stock Drive Products Logo
The Gleason Gear Encyclopedia is available for sale at the site:
http://www.quikey-c.com/gleason/SKUDetailsGLEAFGL6000.Asp
The American Gear Manufacturers Association provides standards for sale on-line at the site:
AGMA Logo
According to Shigley and Mischke’s Mechanical Engineering Design (McGraw-Hill 1989) experiments show that the tensile stress supported by a threaded rod equals that of a rod with diameter that is the mean of pitch and minor diameters of the threads. Thus, the tensile stress area of a threaded fastener is computed from the average of its pitch and minor diameters.
http://www.instockfasteners.com/Tools/ScrewThreadTables.ASP
http://www.marfas.com/machinescrewtapping.shtml
This site also shows the various types of machine screw heads.
http://www.engineersedge.com/screw_threads_chart.htm