When it comes in, take the nut off and swing by hardware store. I do not suggest galvanized nuts they can let off a smell when heated.

So you'll see a "bolt" and "lock nut" the lock nut is the part with the nylon, it should be removable and swapped for a "jam nut" there may also be some with no nuts and just a threaded insert that will also be no problem.

If I'm following correctly based on all your comments etc.

"T bolt hose clamps" is what your looking for. 2.5inch is 64mm and a 10 pack on Amazon for 26$

Lmk if you can't find them and I'll get a link.