Originally Posted by
HillRider
The difference isn't exactly the thread pitch (i.e. the number of threads per inch) which is the same, but the thread form. English threads have a 60° included angle while the Italian threads are 55°. As noted they will work with each other but once you make the change, stick with the new thread form.
Ah, I was confusing pitch with angle, thanks. For the record, Sheldon didn't say pitch, he said angle.