Parts with threads

 From:  mickelsen
4140.1 
I want to create some bolts (and other things) that have threads. It is easy to make a profile of the bolts and then rotate it to get the correct shape, but it don't see how to add the threads. I'm sure that it has something to do with the helix but I can't see how to get the V shape of the threads.
Can someone help me?
Thanks,
Mark