The answer from gnu - McGrath... tap and die. was incomplete.
Of course he should have said "tap and die from Sears."
But those are one of the few items that usually are clearly marked as "not warrantd against normal wear and tear."
The honest answer is that you can't re-thread your male thing without using a smaller thread diameter than what was originally there, and the reduction in diameter required to properly rethread to fit a diferent-threaded nut means that the shaft (or other part that's rethreaded) will probably break almost immediately when you turn anything on.
The complete gnu answer is that any decent mechanic can readily proceed resolutely until everything is irreparably broken and it will be quite clear that the only thing to do is to buy a new thingy. It's more of a "decision avoidance" thing than a make-do fix.
A common ball cap in US aircraft shops says "If it ain't broke I ain't fixed it."
(Management in most places has not yet figured out the other way one can interpret the statement.)