Casper wrote in
:

I re-acquired a butcher block cart my father and I built years ago. A
bit of abuse but bones in good shape. One issue is omni-directional
metal wheels. They came loose but damage to the nuts and holes
moderately loose. Was easy to unscrew from wood but thread nuts came
out with wheels and I'm unable to separate them from wheel shaft.
Thread nuts are brass. I'm short on tools and hate to waste perfectly
good metal wheels because nuts are stuck. Any ideas on how to separate
shaft from thread nut without damage to either? Thanks

I've seen suggestions of using candle wax as a penetrating agent. I guess
you get the parts hot, melt a bit of wax on the threads and it runs down
the threads and capillary action will draw some wax between the threads and
break the bonds.

I haven't tried it, so can't say how well it works.

Puckdropper