Just wanted to call out to this site before I take a die and destroy an intended inference that has a purpose, perhaps like a rocker arm nut.
Even with an interference fit - they should still start cleanly. As I understand it interference fasteners are first threaded oversize for entire thread length - and then threaded true for perhaps a quarter of the threads. This allows them to start and then get tighter and tighter as more of the over-size threads are engaged.
