I know it is not standard practice to model the threads on a bolt or screw but I thought it would be a good exercise. These are my first models using a design table to enter the parameters diameter, pitch, length, width across the flats and height. The models were done with the student edition of SolidWorks 2007. I will probably do the same exercise with the student edition of AutoDesk Inventor 2008. The solid models can be moved to and from AutoCAD, Inventor and SolidWorks via the ACIS file.
This one is for a short bolt with a finished hex head, full length threads
this one is for a long bolt with a finished hex head, threads shorter than the length of the bolt.
Bolt