Best way to cut steel?

[Chilli]

I've got a steel plate 3mm thick and I want to cut a square out of the middle. What's the best/easiest way to do it? I was gonna buy one of those dremmel things, but thought I'd ask first.

Any help would be appreciated.

Cheers.

[andy-xr]

Drill then jig saw?

[unclemark123]

drill a hole, then fine blade in a jigsaw HTH

[m3jappa]

Angle grinder with metal blade would be my choice, but much like a jigsaw will require a steady hand.

I suppose it depends how large the piece is, if its tiny then yes a dremel may be better.

[Chilli]

Ah ok....Jigsaw will do it then?! Got all those.

Many thanks.

[DAVEVO9]

Chilli said:

Ah ok....Jigsaw will do it then?! Got all those.

Many thanks.

Use a lubricant on the steel while you are cutting.. WD40 will do.. You will soon burn out the blade if you don't

[madbadger]

Best way? With a laser or a waterjet cutter.

Most pracical? Jigsaw will do it but 3mm is fairly thick. Presumably it doesn't need to be perfectly square? A heavy duty nibbler would be better if you can borrow one, but you'll still have some degree of radius in the corners.

[AJS-]

Don't be a wimp. Bite it.

[andygo]

madbadger said:

Best way? With a laser or a waterjet cutter.

Most pracical? Jigsaw will do it but 3mm is fairly thick. Presumably it doesn't need to be perfectly square? A heavy duty nibbler would be better if you can borrow one, but you'll still have some degree of radius in the corners.

Heavy duty nibbler?

Send her round here please.

[spikeyhead]

You'll struggle to get through 3mm of steel with a jigsaw.

Use an angle grinder or gas axe.

[M400 NBL]

Yep drill 2 holes in opposite corners of the square, then jigsaw from those to the other 2 corners.

[john2443]

In the absence of a water jet, laser or wire-eroder, drill a line of small holes (say 3mm dia) all the way round - this will be MUCH easier if you have a pillar drill - then use a coal chisel to split the small webs left between the holes and finally file off the peaks and get it to the right size.

Or, does it really have to be the middle - could you use 2 pieces half the size and screw them down when in use, or weld them together.

[Pesty]

john2443 said:

In the absence of a water jet, laser or wire-eroder, drill a line of small holes (say 3mm dia) all the way round - this will be MUCH easier if you have a pillar drill - then use a coal chisel to split the small webs left between the holes and finally file off the peaks and get it to the right size.

^^^

Let the drill take most of the material away

[Pupp]

Those tile cutting ropes in a fretsaw/jigsaw type style work fairly well for small jobs if some degree of precision is needed. Clog fairly quickly in ally but I've had pretty good results in steel and stainless etc

[Snake the Sniper]

If it's a smallish hole, get a couple of the 1mm cutting discs for a grinder and set to. Won't take long, but make sure you wear ear plugs and eye glasses, as grinding dust is a right bd to get out of your eyes. And 3mm plate will ring like a bell if not fully clamped down when you cut it.

[SS HSV]

Nuke it from orbit. It's the only way to be sure.

[eldudereno]

As others have said, it all depends how big the hole needs to be. Also, if you need to ask how to do this you've probably got very few tools so you'll probably end up hacking it out.

[thinfourth2]

3mm a decent metal blade and go slowly with a decent variable speed jigsaw and you will piss through it.

Thats how i cut holes in gas bottles

[El Guapo]

john2443 said:

then use a coal chisel

If you can´t lay your hands on one of those, try a cold chisel

[IANinBCN]

Thermite. That'll do it.