On Nov 3, 1:32*pm, 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.

on 1/4" aluminum, a typical Unibit(tm) isn't going to help. I have
one in my desk drawer as I type this, I hauled it out and looked at
it, and it won't do more than 1/16" in one pass and 1/8" from both
sides. For a nicely finished hole, unless you have a 1/2" drill
motor, a hole saw is your best choice. Choice #2 would be to buy a
proper 1/2" drill and a 3/4" bit with a 1/2" shank (pref. w/ 3 flats)
but that could easily run close to $200. Most bits that size start at
$20-30 and go up from there for fancier coatings, etc. Of course
depending on the definition of "several" that might be the way to go.

nate