Rather interesting that a two-year old post is still relevant in providing useful information. I have an old NOS Campy Sport (still wrapped and in the box) headset that I have never used because one time I tried to screw the locknut on to a Zullo fork and it just would not thread on. After reading the posts and seeing this picture I was able to identify the headset as Italian and not French which I thought the F meant! This time when it would not thread on by hand I took a wrench and after about one and one-half turns it threaded on, by hand, just fine.