RE: [VAL] Re: Cutting round holes in AL

["Peter Ryner" <pryner@xxxxxxxxxxx>]

Real name is a grommet.  They come in all sizes and I agree with Daisy, they
are a must if you are running wire through a hole.  Ditto on the
weatherproof connecter.

A hole saw will cut a pretty smooth hole, but you have to have a quality
saw.  There are some really cheap tools out there and they will dull very
fast.

The only "knock out" that I know of is in electrical boxes where they are
made with holes that are nearly cut through.  The electrician "knocks out"
the remaining material to make a hole to run wires into the box.

I have seen a hole cutting tool in my old aircraft maintenance days that
cuts a round hole by tightening a bolt to draw two pieces of a die together
which cuts the metal.  Not very easy to use unless you have access to both
sides of the metal.
Pete