I just installed C3.01 and was interested to see that the fix includes some work on booleans. I decided to play a bit. First I made a spiral thread in the spline modeler and converted it to a vertex model. Litst has a tutorial on this at: http://www.chez.com/litst/eng/home.htm in addition to many other goodies.

Working in the vertex room I added a cylinder and made a few modifications to make a blank bolt.