How to drill a 3/4" hole in metal?

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

Reply to
Walter R.
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3/4" drill with 3/8th shank?
Reply to
Sharp Dressed Man

Try a 3/4 inch drill with a 1/2 shank.

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Reply to
tnom

Buy a hole saw. They make bits that are large and have a shaft that matches a 3/8 drill motor. Maybe a step bit if you can drill from both sides.

Reply to
Ralph Mowery

Aluminum is not difficult to drill through. Use a hole saw or a unibit. Take it slow.

Reply to
John Grabowski

Try a 3/4 inch hole saw.

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Reply to
tnom

How many holes?

Aluminum can easily be worked with tools meant for wood

cheap methods follow........

1) Use a 3/4" spade (aka paddle) bit. 2) Use a 3/4" Forstner bit 3) Use step bit but 1/4" is a little thick for a step bit 4) Use a hole saw

don't allow the bits to overheat cheers Bob

Reply to
BobK207

'Try a tapered reamer

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Reply to
tnom

hole saw?

nate

Reply to
Nate Nagel
3/4" bi metal hole saw. Should take about a minute or less per hole. s

Reply to
Steve Barker DLT

Drill a 3/4" hole.

Reply to
Doug Miller

All kinds of ways.

For example, many electricians have a "Greenleaf (sp?)" punch.. To use it you drill a 1/4" hole, asemle the male and female parts of the punch with thru bold on the 1/4" hold and tighten the bolt. In about 30 seconds you have your hole.

I have had to make holds for "stuff" in the top of stainless steel sinks. Usually, I just used the biggest drill I had (usually 1/2") and then used and "ball" or "cone" shaped grinding wheel to enlarge the hole.

An Al, you might be able to use a reamer.

Or you can use a saw to roughtly enlarge the hole and then "polish" with a grinder wheel as above.

Except for the punch, the results usualy aren't pretty but you usually cover up the hole so who cares.

Reply to
John Gilmer

It's a tedious job to

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Works great.....Paul

Reply to
catguy

How about a 3/4" hole saw?

Reply to
Boden

You can get a set of knock out punches from Harborfreight.com for $15.99. It has 1/2, 3/4, 1 and 1 1/4 sizes punches and dies. Up to 10 gauge steel, aluminum, plastic and fiberglass.

Reply to
Claude Hopper

Those are nice, but he did say 1/4" aluminum - even a real Greenlee punch might have a hard time with that.

nate

Reply to
N8N

"John Gilmer" wrote in news:490e7b18$0$20783$ snipped-for-privacy@reader.usenetall.se:

Not for .25 inch thick material.

Reply to
Jim Yanik

Go to the drill bit section of your local hardware store. They should have hole saws in that size. Not totally precise sizing, but reasonable. Should cost between eight and fifteen bucks.

Reply to
Stormin Mormon

My Greenlee punch set has no problem with

1/4 inch soft aluminum. I'm sure there are some aerospace grades that might break it. Anyway, a 1/2 inch conduit punch cuts a 7/8 inch hole size. (0.885 inches to be precise) Which is why I didn't post it as a suggestion. A mechanical punch for an exact 3/4 inch hole can be obtained but the price may be very high as opposed to that of a standard widely available conduit punch.

TDD

Reply to
The Daring Dufas

I guess we would need to know if the OP is going to cover the holes before we can say "who cares".

I've drilled many holes that do not get covered up, so I usually care what they look like.

One trick I like to use when drilling metal, especially on a drill press, is to clean up the hole with a bit that is a few sizes bigger than my hole. Slight pressure on the press will clean up the rough edges and impart a slight inward bevel. It looks nice, especially with exposed holes.

Reply to
DerbyDad03

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