"tim" wrote:

Sulferized oil works best for 304 stainless .Dark thread cutting oil
is the same stuff.

Oil is toxic and so is the solvent to clean the oil off the parts.
You need to dispose of such toxic waste properly but it can still come
back to haunt you. I'd much rather use something that gives a good
result but can merely be dumped down a drain. Have you even tried any
of the non-toxic coolants I mentioned?

--
Jim