On Mon, 03 Nov 2008 13:55:55 -0600, The Daring Dufas
wrote:

RickH wrote:
On Nov 2, 7:04 pm, "Walter R." wrote:
I need to make (drill?) several 3/4" holes in 1/4" thick aluminum panels.

I have a 3/8" drill, a 1/2" drill bit, a 4" angle grinder, and hand files.
It's a tedious job to drill a 1/2" hole and then use a file to enlarge it to
3/4".

Any easy way to do this without getting blisters?

Thanks

--
Walterwww.rationality.net
-


God I'm surprised only one guy told you the right answer... You use a
"step bit", Home Depot has them, they are cone shaped and cut 1/16 or
1/8 inch per step, you stop pushing when you hit the 3/4 inch step.
They cut very fast, clean, and round especially through aluminum, but
set the drill slower for aluminum. They are not cheap bits but well
worth the money for metal fabrication jobs.


I use step bits all the time in aluminum. My
only suggestion would be to use a lubricant.
I use either a liquid lube made for aluminum
or saw wax. A tube of saw wax looks sort of
like a chap stick on steroids. I've used Tap
Magic cutting fluids for years:

http://www.tapmagic.com/

Saw wax:

http://www.relton.com/cutfluid2003.html#stick

I stick my drill bit into the wax and the wax
will melt from the heat generated by drilling
which will lube the drill bit.

TDD