Drilling stainless

Try a plumbers merchant they do punches for tap holes in sinks, Ikea sell them too for their sinks, though they didnt have one when I had to unstall one of their sinks and it took a very long time with a good quality holesaw (Starret)
 
What no one has clearly mentioned is that an ordinary 700Watt electric drill does not have enough torque at low speed to drill stainless. I have had problems as you have many times using a small electric drill and a cheap pillar drill using HSS, stainless and cobalt drills.
If you get a bigger electric drill say 1050 watts with variable speed control and use the low speed with constant pressure to avoid work hardening as others have said, you will be surprised how much easier it is.
 
I once had to drill a 25mm hole on a 3mm thick stainless steel plate, it was the occasion to see for the first time a most interesting naval forging shop.

They had vertical drills with bits up to 40-50mm diametre; they were forging shackles for naval chain which were 50-60cm high, they had a strange machine with something like a drill bit but of different shape which was used to drill the 10cm hole in the end of the shackle.
Massive things, never seen anything like that before, imagine taking the steel fittings you have onboard and enlarge them 50fold.

If you find a similar place, I suggest you ask a lot of questions about their job and look everywhere showing a lot of interest in the machines, it will be natural and they will probably do what you need for free :)
 
re thin discs:
2nd_apprentice said:
Yeah, got those for my Dremel. Works a treat too but not so great for cutting holes unfortunately :(
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I designed what I wanted with square and triangular holes!
I meant the thin 0.5mm discs that go in a 4 1/2 inch angle grinder, they cut stainless sheet like it's cheese.
No use for a 25mm hole though.
I would go with the punch, I've used them on 1.5mm stainless to make holes for electrical connectors.
Of course there are many flavours of stainless!
 
However you decide to drill it make sure it is securely clamped. Cutting big holes in thin sheets is quite dangerous. If the drill catches the sheet could take your hand off.
 
PhilipH said:
see here http://www.electrix.co.uk/pdf_downloads/electrix_drilling_guide_en.pdf

I always use lots of cutting oil which makes a huge difference, but not easy to come by and I don't have a current UK source. Anyone out there with a supplier of small quantities retail?
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For small work you might consider a cutting compound:

http://rocol.com/products/view/124/rtd-metal-cutting-compound

Available in retail size here:

http://www.tooled-up.com/Product.asp?PID=8402

This stuff is extensively used in the aircraft industry. You could drill stainless with the end of your ole grannys garden dibber.
 
CreakyDecks said:
However you decide to drill it make sure it is securely clamped. Cutting big holes in thin sheets is quite dangerous. If the drill catches the sheet could take your hand off.
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Very good advice. I also wear heavy gloves when drilling metal sheets. FWIW, I've had some success drilling S/S with cobalt-coated drills from Lidl - start small, and enlarge the hole to suit. I have a bottle of Dormer Supercut fluid which improves things. That said, for anything heavy duty, I prefer to get a local engineering shop to drill or punch holes.
 
Bit late on this one. But I do this all the time, and up to 10mm thick and 50mm diameter with hole saws. OK I use a decent pillar drill for the big ones, 25 mm is OK with a hand drill. Just needs to be sharp (both drill and cutter) and wet (3in1 works) and slow.
Clamping between ply is handy to avoid grabbing on thin stuff like .5 and if you 'pilot' the top sheet, then there is no need to use the centre drill as the ply guides the hole saw.

By hole saw, I don't include those multiple sized ones with cheap strips of blade in an ally holder. Bi-metal by someone decent. Starratt Sandvic and BIN come to mind. Even a fresh one from Screwfix could be good. Another tip, in the larger sizes on quick change mandrills, allow them to back up to the end of the thread, rather than use the locking pins. Less chatter and wear.
 
VicS said:
they still need a pilot hole, (13/32" for a 1" punch) to be drilled first and somewhat larger probably than the pilot hole the OP has failed to drill for his hole saw
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Even so it is potentially a lot better than trying to use a holesaw, got the tee shirt did it but it would have been so much easier with the punch but it was Xmas eve. A couple of half decent twist drills will get the pilot sorted and the punch really works and gives a decent finish
 
On 0.5mm stainless, you can probably do the pilot hole with a big centre punch, a block of (fire)wood and a nice big hammer!

Sometimes the old ways are best!

But seriously, carbide spade drills like you use for ceramic tiles work a treat. Lots of water to cool it.

I'm disappointed nobody has suggested chemical etching or spark eroding yet.
(how do you make big holes in thin sheet? by being rubbish at arc welding!)
 
Why aren't you using (polished) Copper? It's supposedly the best at drawing heat away, and reflecting heat into the cabin. Easy to machine too.
 
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