Quote Originally Posted by th62 View Post
Good idea, probably not many have noticed but the head on cap screws is not concentric to the threaded shaft. If you chuck the threaded shaft and turn the lathe on, you'll find it is a little eccentric. I only noticed this when polishing the heads of Allen heads for my custom TX650.
After you use the socket to drive the screw to turn down and re-thread the screw, it will be concentric. As least within the tolerance of the fit of the wrench into the socket.

I often use old or new bolts as stock to turn into other things I need. Chucking a clean bolt in a collet, I have discovered that neither the hex head or the threads are concentric with the shank on most bolts. I doubt it would cause any issues in most situations.