Rectangular Holes

[Eoin]

Hi,

I'm working on a few small DIY audio/electrical projects at the moment, and I've hit a bit of a brickwall. I need to cut or punch a rectangular hole in a metal sheet in order to install an IEC power connector. I'm not sure if the external dimsensions of an IEC are standardised, but the one I have is more or less 19mm x 26mm. I realise I could drill a hole and file it out, but tbh I've never managed to file a hole to a standard I was satisfied with. Any ideas? Is there some kind of punch or chisel that would do what I want?

[IBM5081]

See http://www.lawson-his.co.uk/images/Q-Max/q-max.jpg
This one is rectangular and appears to operate similar to a Greenlee slugbuster. There are square ones as well.
For a cheaper solution, put a fine-tooth metal-cutting blade into a jigsaw and clamp the sheet metal to a plywood backing to reduce the vibration.
It just depends on what you want to spend on it.

[majakdragon]

Eoin, Welcome to the DIY Forums.
Have you thought about using a Dremel with a cutting wheel? The wheels are small and give you good control. Good luck with your projects.

[GWIZ]

I used this style of nibbler works good.
You start with a 3/8" drilled hole about.
http://www.doityourself.com/store/u628203.htm

[Phil H]

Greenlee has punches like Carter has pills; squares, rectangles, even odd shapes like an rs232 (http://www.greenlee.com/). They may be a little pricey if you only have a couple holes to do. Here's a link to there holemaking catalog - but it is a big pdf file to download: http://199.248.241.8/greenlee/holemaking.pdf

[Eoin]

Hi guys, thanks for the responses.

How do these punches work exactly? I really don't think I could get as good a result from any kind of saw, and tbh I'd rather spend a few quid and be happy with the results.

[Phil H]

Eoin,
The punch uses a screw between two halfs (punch and die). You drill a hole through the panel in the center of your rectangle. Insert the screw (with the die) into the hole. Then, thread the punch onto it from the other side. Tighten with a wrench and it punches the hole. They also make a hydraullic set-up which can be used instead of screw.

[Eoin]

Ah, now that makes sense. I was sitting here thinking it was something like a centre punch... :rolleyes: Cool. I'll (hopefully) be doing quite a few projects like this one over the next few years, so I think investing in a punch or punches is the way to go. Thanks for the links, guys.