On Sun, 7 Sep 2003 10:41:06 -0700, D.B. wrote:

Back up as it starts to get tight, don't wait until it's
tight.

I do that. It just doesn't take very long; certainly not two turns.

Are you using the right size tap drill for the material?

Yes.

Don't have good tap drill chart?

I do.

Subtract one thread pitch from the nominal screw diameter.
.250-20 Tap drill = .250 -1/20 = .200. Then pick the next
largest actual drill size (assuming you have a complete set
of drills).

If I can remember all that, I'll try to use it if my chart isn't
handy.

If you only have a set graduated in 1/16th or
32nds you have a problem.

I have fractional and numbered, but I don't have letter size. Most of
the time I'm tapping sizes that need number sized bits. No problem
there.

Also use coarse threads everyplace you can. They are easier
to cut and hold up better in many materials, cast iron and
aluminum being two good examples.

Probably stainless, too, I would think, because of the ease of
galling.

Thanks for your thoughts.


LRod

Master Woodbutcher and seasoned termite

Shamelessly whoring my website since 1999

http://www.woodbutcher.net