DIYbanter - View Single Post

Grant Erwin wrote:

wrote:
.. I had intended to drill a 1/4"
diameter hole first and then square it with the punch.

I submit that this is a really bad idea. Unless you make up a punch that has a
1/4" guide pin, you'd never be able to locate your hole, so your holes would be
randomly located to some degree. Further, drilling stainless sheet is itself a
bitch which you do not need to do if you're going to punch it.

Properly set up, a punch makes very minimal distortion. If there were some, you
could always set the piece between blocks and tap on the top block with a hammer.

It seems some people are responding to this posting with the impression that you
may have to also put square 1/4" holes in stainless up to 1" thick. I hadn't
seen this, but if so, punching is out of the question for material that thick
and it would take a very large machine to do such even if you could find a punch
that wouldn't shatter. On the other hand, broaching doesn't make sense for sheet
metal. A small square hole in sheet metal? NO BRAINER - punch it and be done.

GWE

The best way to do it is to sub it out to a guy with a waterjet cutter.
Have him cut the sheets to size and cut the square holes. You then
don't have to handle the full sheets and the holes, as well as the cut
sheets will be within a couple of thou. We sub that type of cutting
out. That is the reason we are getting rid of the punch presses.
For .062 stainless 304 steel the cutting rate is about 120 inches a
minute.

John