N8N wrote:
On Nov 3, 8:16 am, Claude Hopper
wrote:
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
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.


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

nate

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