iab

So I went to Sheldon's site and found an Iso axle thread is 1 mm. I also know from experience the French have different threads even though it is also 1 mm. I can confirm this because I have measured English, Italian and French axle threads and they are all 1 mm.

But nuts are not interchangable, at least I don't think they are.

I also measured diameters: Front French - 8.00 mm, Front Iso - 7.88 mm, Rear French - 9.50 mm, Rear Iso - 9.46 mm

I understand the front but the rear is a .04 mm difference, well within manufacturing tolerances, yet I can't exchange nuts.

Is this a thread pitch thing? Does someone know the differences between the different axle types?

el twe

I believe it's pitch. I can tell you from experience that Shimano cones will not thread on Campy axles, but the locknuts (fewer threads) can be forced on.

MnHPVA Guy

Campi, Miche, Joy Tech and a few others use 26tpi with metric diameters, 10 or 9mm. 1mm pitch = 25.4tpi. Close enough when there are only a few threads that you can install a Shimano derailleur into Campi hangers.

Italian threads have a 55 degree angle instead of 60. Close enough in most cases.

iab

Yes! On closer inspection it is 26tpi vs.25.4 tpi. That is why it will go 4-5 turns before getting jammed up. My problem is with wing nuts and the threading is about 1/2" long, too many threads to work.