In article ,
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writes:

I bought a hole saw from Harbor Freight (yes, I know) and I chewed up
the set screw. I'm pretty sure it's a M5 x 1.0. Any kind of screw
head configuration would be OK, but I'd prefer anything but slotted so
that I can crank it down hard. But I can't find this screw size/pitch
in any configuration. I've looked at lowes, home depot, grainger,
mcmaster and fastenal with no luck.

Your metrology is likely mistaken.

Or it's just a little off and the screw is a 10-24. An M5X1
thread is not unheard of, but I can't imagine why it would
be used on a holesaw and the chances of finding an M5x1
screw are pretty slim.

My bet's on the 10-24.

Ned Simmons