On Mon, 11 Mar 2013 12:24:16 -0700, Gunner wrote:

On Mon, 11 Mar 2013 13:08:35 -0500, Tim Wescott
wrote:

So I'm fabricating some stuff out of 40 mil 304 sheet ('cause that's
what I could get from McMaster -- I know now it was a Bad Choice for
doing lots of drilling and whatnot).

Thanks to some input here, I'm doing pretty good, but I noticed that the
sheet seems to be fairly well annealed on one side, but really hard on
the other. Trying to drill 1/16" holes in the stuff, it makes an
enormous difference (like, between success and failure with a side of
broken drill bit) whether I start drilling on the "good" side or the
"bad" side.

Is this common?

Yes unfortunately.

And always remember

"303, thats for me!"
304..shes a whore!"

Yes, I was thinking that when I was looking ALL OVER for 303 sheet about
that thick.

I have figured out the right feed rate to drill the stuff. It goes
through like I'm drilling really hard lead (if that makes sense), with a
"crack!" at the end when it breaks through the hardened material.

It does dull drill bits amazingly fast -- I didn't used to be able to
sharpen 1/16" drill bits by hand on a grinder, but I sure am now!

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com