Drilling Big Holes...

Hi svart
I meant for square openings.
yes on holesaws for the roundies

Oh yeah I understand. My comment was a reply to some of the other posters who mentioned steel wearing down the holesaw. If you buy the cheap ones they don't last even when drilling wood. If you buy the good alloy ones they last for years as long as you don't un-temper them by overheating.

You know what... Laser cutting is surprisingly affordable. Rather than sweat in the workshop and potentialy kipper your tools on harder materials, why not look in Yellow Pages and give the local Laser Cutting firm a call? I got a quote this week and was surprised at how affordable it is.

Ironically, with one laser machine they have, they can only cut alloy to 3mm, yet steel to 12mm! It's to do with reflection quality of the metal grain or something.

Treat yerself to a 2/3mm steel panel, powder coated + engraved - nice!


Justin

In Aluminium, I use a hand router with a 6mm (standard wood-type) bit, running 25.000rpm - and a precut plastic/plexiglas/acrylic template to control where the router goes. This takes A LOT of oiling - ca ½dl paraffine oil for a standard sifam vu-meter..

..and then some filing at the corners..

:!: Will not work in steel or brass plates..

Jakob E.

[quote author="mitsos"]hey kazper,

how nice(or not so nice) are the holes with those manual punches?[/quote]

The greenlee's punch very smooth, the HF cheapies are not as smooth but by far smoother than you could cut with a jig saw, etc.

With any of these punches make sure you notice the 4 marks. If you make a + sign with the center as center of your hole, you align the tic's on the 4 marks and you will be perfect center provided the + is square.

[quote author="Svart"]I'd still vote for a holesaw. For steel, just use a bi-metallic saw. They'll last for years cutting steel as long as you cut with the right speed and don't overheat the teeth.[/quote]

I'll add : spray with a drilling/cutting cooling and lubricant, they will last allot longer and should provide a better hole.