Ed Huntress wrote:
drill .250" holes in radiation hardened 316l stainless while spraying
the unit with mercury... 1" thick stainless with no coolant.
I'm guessing that I need to run at 50 RPM or less. Any thoughts?

1) Don't do any testing or applications engineering in your plant.
2) Study up on hazmat gear.
3) Make sure your life insurance is paid up.

Adventures in machining. Sounds like this is one of those ISO 9002 or
whatever jobs where you document the materials used (test results from
steel manufacturer) and of course, all the SPC data or whatever from
your shop.

Mercury as a coolant? What is the purpose? Better think of how the unit
will be wiped down after machining (bet it will be anally probed, fer
sure). Is there a chance that the mercury will become atomized by the
cutter, or vaporized by the heat?

What if your setup leaks? What's the spill containment plan? Will you
test the operator prior to machining and after machining to detect exposure?

How will the presence of mercury be monitored for during machining? Is
there a requirement? HAZMAT suits are great, but is the machine in an
isolated room, or part of an open bay shop?

How will the entire exposed working area of the machine be tested, and
by who? Licensed or approved by OSHA?

How long will it take to decontaminate the machine? Are the surfaces
either painted / coated / finished so mercury does not bond / soak in /
hide in crevices?

Be up front with the customer on the clean up costs and requirements. If
the numbers don't come out, try to help the customer find a shop that
can do it. Better do a lateral pass if you can't handle it correctly...

Imagine accepting the job, doing it, then finding out you have a
persistent mercury contamination issue where that machine is not
starting on another job because it's dangerous to touch.