Drilling Stainless Steel

From:  Edward V. Phillips [SMTP:ed-at-alumni.caltech.edu]
Sent:  Friday, May 29, 1998 3:40 PM
To:  tesla-at-pupman-dot-com
Subject:  Re:  Drilling Stainless Steel

"Hi All,
        Like many people, I like to use two large 12 inch salad bowls as a
top terminal.  For my new one, with built in current sensors, I had to drill
5 holes through the bowls.  WOW! was it hard.  The stainless steel in those
things must be very high in chromium content or something.  I trashed a
number of nice drill bits.  The titanium nitride bits work for a moment then
just slide on the surface.  If anybody has any better ways to drill nice
holes through this stuff, I would love to know about it.


        Terry Fritz"

	Common experience!!!!!  Punching works better.  The stuff
work hardens and I have had some drilling success using special
stainless steel drilling lubricant (mail sample from long ago)
and feeding the drill in very hard, but not very satisfying.
I have also used a center punch to dig a hole through the things
(backed up with wood, of course) then used sheet metal snips
to enlarge the hole.  Whoever invented the miserable stuff was
no friend of machinists!!!  I'll ask you a question.  How do
you handle the rolled edges on the bowls???  In the old days when
you could get aluminum bowls it was pretty easy to turn the rim
with a fine saw to separate pieces of it, and then peeled them
back with needle-nosed pliers.  Have never done a satisfactory
job this way with stainless bowls.