Rockwell combo sander problem

[challenger]

I have a rather old Rockwell disk/belt sander. It's a great machine IMO. It recently became really noisy and threw the belt way off to the side. It turned out that the shaft for the top roller lost the jam nuts and the shaft slide to the inside and was no longer in the bearing. These jam nuts at 15mm-24 pitch thread and there are none don't list any that size. I looked to see if any are available locally but no luck . I looked on Amazon and they don't list any this size. Any ideas?
Thanks.

[darryl]

If you don't want to make them, perhaps you could shrink fit an aluminum collar.

[challenger]

I just edited my OP. turns out the shaft is 15mm but uses a 24 pitch thread??? What is this about?

[reggie_obe]

Two pitch choices in M15: 1.0 and 1.5

[challenger]

Funny thing is that it's neither of those. 24tpi is very close to 1mm but it is definitely 24TPI. I suppose this is due to the bearing bore being 15mm but the USA made machine made the powers that be use a 24 TPI thread on a metric shaft. I read elsewhere that this is indeed the case.
I'm going to make some nuts tomorrow I hope. I've never done internal threads and the internal thread tool I have was procured with the lathe and needs to be ground for the fine pitch. It just a piece of round hss ground for internal threading. It will take some extra checking things out time iykwim. The sad thing is that I can't locate my thread gauge 😤

[RWO]

Why recreate the bastard size? Just make a new shaft with a snug sliding fit in the bearing and use a dab of Loctite to lock into final position.

RWO

[challenger]

Already made the nuts. Or I am in the process. I have a cylinder internally threaded and have flats on opposing sides.