Roger Mills wrote:

It's best to use *three* nuts. Lock 2 of them together and put the 3rd nut
further along the shaft. Clamp the middle and third nuts in the vice - with
the first nut just outside the jaws, so it doesn't matter if the flats don't
line up.

That works fairly well except that in the bandsaw there is only a tiny
gap between the vise and the blade. Enough for a quarter locknut
perhaps. I could put a locknut at the other end of the vise, but that
won't work when the rod gets short.

When cutting a threaded bar or bolt, you should always have a nut on it
anyway - so that subsequently removing the nut will clean up the threads
where the cutting process may have damaged them.

Agreed.