On Sep 1, 5:33 am, wrote:
I have a 1/8th thick aluminum bar 36 inches long and 2 inches wide
that I want to drill some 5/16 inch holes into and bend to 90
degrees. Could a hand held drill be used to drill the holes or would
I be better off taking it to a machine shop. If a hand held would do
it what specifications would the drill have to have to do it?

Thanks.


I learned YEARS ago that aluminum can be easily worked with common
wood working tools.

Miter saw, table saw, router, drills just use sharp carbide blades /
bits.

What alloy are you using? Most common extruded shapes are 6061 or
6063.

Flats (what you have) can be a wider range.


I would strongly suggest laying out the hole pattern & center punching
the holes locations BUT bend the material BEFORE drilling the holes.

The hole will change the local stiffness of the bar & the bar might
have a tendency to "kink" at the holes when you bend it.


Once the bar is bent you can grip the bar in a vise or "work mate" or
clamp it to a 2x

Drill 1/8" & then go for it with the finished size...... a little
kerosene would help but anything is better than nothing, high speed is
better than slow speed.

On my press I find something in the moderate range works best. Probably
about 3200 rpm but I'm guessing. Too fast and you get too much heat,
too slow and all it does is grab.

Kero tends to make the bits grab a lot harder unless you're using low
angle bits. Regular thread cutting oil (not a lot different, I know)
doesn't seem to cause that "grabbing" so badly, especially just before
punch-thru. It's also better to drill from both sides if you can. If
not, just back it up with apiece of wood is usually enough.


If you have any waste material do some practice drilling

cheers
Bob