Cutting neat holes in sheet metal

[bricol]

Drill hole, insert pad saw. Cut opening, file to final finish.

Or just use a slitting disc in a grinder. If you're being really flash, drill a hole at each corner and cut into the hole.

I despair sometimes at work. Watching people using excessive technology to create something people has just got on with and done for many years - Mark out, cut, remove sharp edge.

 

[Martin-Sy]

@bricol Your 6000th post!

 

[Ian X]

You might be right, although I haven't designed it yet so finishing it might be optimistic!

I've never tried a jigsaw on thin (0.8 mm) steel. It must need a really high TPI blade (to keep three teeth in the cut it'd have to be 96 TPI I think!).

I glued a piece of 1mm stainless to a piece of 1/4" birch ply to cut a curved instrument panel to shape, it worked well. I dunked the piece in petrol to soften up the petroleum glue, it came away easily enough.

 

[MetalMonkey]

Another vote for step/come drill and just cutting or chain drilling the squares and filing to fit. A good sharp file makes surprisingly short work. If it's thin sheet clamp a piece of wood as a backing just past where you are filing to provide strength and cut down the noise and vibration.

 

[gaz1]

if you want straighter then use a pantograph

 

[marlinspike]

We used a Q max punch type thing for the holes when we fabricated a new battery tray. I was surprised how quick and neat a job they do.

 

[mart]

@DR.AL

I have only read page one as the subject is quite lengthy. The members have come up with quite a few suggestions. Would a cone/step drill be helpful for SOME of the holes. Also I assume a small warn down cutting disc may help for some of the square holes.

 

[timgunn1962]

I use Q-max cutters for the round holes in common sizes (22mm for switches, etc. 20mm and 25mm for glands). Jigsaw with T118AF blades for square/rectangular holes in steel panels, or T118AHM, the Carbide-toothed pricy ones, for stainless steel panels. Tape the panel first to avoid scratching the surface. 10mm starter holes just inside the corners (at least 2 diagonally-opposite) means the cuts are reasonably straight and easy to control. Holesaws get used for odd-sized round holes.

If using holesaws, there are a couple of tricks to avoid wander.

One is to drill the pilot hole (usually 1/4") then use the holesaw with a bit of rod instead of the pilot drill. It stops the holesaw catching and causing the drill flutes to enlarge the pilot hole. The other is to run the holesaw through a bit of scrap (I usually use MDF) remove the pilot drill, clamp the scrap to the workpiece and run the holesaw through, piloted on the hole in the scrap. It's also a relatively easy way to get discs of metal.

As others have said, the Carbide-toothed holesaws tend to prodice much tidier holes than the bimetal ones. I think they use smaller pilot drills, so check sizing if you are going to use rod instead.

 

[Kram]

Multi tool with metal blades for the square holes.

As in the oscillating type or the rotary dremel type? I find both to be somewhat useless on metal although the small rotary blades can work well in an die grinder.

Another option that I have used is to G clamp a peice of HSS square lathe tool either side of the work and use a chisel to shear along them.

I did the melter control box with nibbler and file, a few photos here:

Stuff you have made today

Not made by me, I just want to show it off. Mum's just finished another animal chalk bag, jellyfish this time. She's gonna try sticking it on Etsy for silly money and seeing if there's any interest. :D

www.mig-welding.co.uk

 

[bricol]

@bricol Your 6000th post!

5995 of 'em bemoaning how people seem to make simple tasks so much more complicated than they need to be, or complaining their local ironmonger has shut, while posting the latest bit of junk delivered from China via the useless (their words) Evri, Royal Mail, Fedex etc . .

 

[oldbikedavey]

There's always the corner drill and cold chisel method, followed by a tidy up with a file.
Keep the good edge down on the vice jaw or other clamping face, and keep the distortional effects in the waste area...
A sharp cold chisel can cut fairly precisely, and quite quickly.....

 

[droopsnoot]

I've used a step drill quite a lot to do 18mm holes in some panels that I make fairly regularly, but the trouble I get with them is that once I've drilled four or five, there's smoke coming out of the side of my drill even though I'm happy to let it do the work, I'm not putting much pressure on it. For that particular job, I bought a suitable QMax punch and it's much, much easier. But I must read through the rest of this thread when I get a minute to see what other ideas are here, as it's something I do quite often, but not very neatly. For the first time in my current restoration (over four years in, and not the first car I've done) I encountered two sections to cut out where a plasma cutter would have been the correct tool for the job, so we can almost guarantee now that they'll never come back into Lidl. And if they do, I'll still be thinking "well, I've done the job now, so do I really need one?".

 

[MattF]

And if they do, I'll still be thinking "well, I've done the job now, so do I really need one?".

That's your problem. Stop with the "need" philosophy & just buy one. It's then available if you do ever need it.

 

[Kram]

That's your problem. Stop with the "need" philosophy & just buy one. It's then available if you do ever need it.

I shall find some more amazons

 

[Jack_K]

I avoid square switches and connectors.

 

[gaz1]

now i spotted this on @doubleboost s post within the back ground and thought about this thread post

portable cnc

 

[RichardM]

Step drill for the round ones up to the size of step drill you have. Chain drill and file to size for the others.