Drilling stainless

2nd_apprentice

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Thought I'd fit a heatshield over my charcoal heater and ordered a 0.5mm sheet of stainless. Got out the hole saw in order to drill a 1" hole for the flue but no luck. Not even making a dent in it. Used a centre punch (at least I think that's what it is, came with the drill bits) and tried "gold" coloured drills as well as the black coloured ones. What next? Somehow feel I'll have to bin it and try something else but what? Copper would be easier I guess but useless as a heat shield. How about aluminium?
 
Thought I'd fit a heatshield over my charcoal heater and ordered a 0.5mm sheet of stainless. Got out the hole saw in order to drill a 1" hole for the flue but no luck. Not even making a dent in it. Used a centre punch (at least I think that's what it is, came with the drill bits) and tried "gold" coloured drills as well as the black coloured ones. What next? Somehow feel I'll have to bin it and try something else but what? Copper would be easier I guess but useless as a heat shield. How about aluminium?

Centre punching it has work hardened it !

Normally for a small number holes a HSS drill is adequate.

A cobalt steel drill might do the trick. Keep it lubricated and cooled.

Aluminium is a fairly good heat conductor although not as good as copper.
copper 403, aluminium 236, stainless steel 24.5 (W/m/°K)
 
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Thought I'd fit a heatshield over my charcoal heater and ordered a 0.5mm sheet of stainless. Got out the hole saw in order to drill a 1" hole for the flue but no luck. Not even making a dent in it. Used a centre punch (at least I think that's what it is, came with the drill bits) and tried "gold" coloured drills as well as the black coloured ones. What next? Somehow feel I'll have to bin it and try something else but what? Copper would be easier I guess but useless as a heat shield. How about aluminium?

Hmm. I drilled some S/S and it took ages. You have to do it v e r y s l o w l y and put a coolant on the drill. it works eventually.

Peter
 
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Can you get to a fabricator and ask them to punch it out? Either Stainless or Ali you're going to struggle with any sort of drill. I haven't seen them in years, but there are things called Cumax Cutters (SP) which are basically a punch and die, garages used to use them for cutting holes in car bodywork to fit radio aerials.
 
Can you get to a fabricator and ask them to punch it out? Either Stainless or Ali you're going to struggle with any sort of drill. I haven't seen them in years, but there are things called Cumax Cutters (SP) which are basically a punch and die, garages used to use them for cutting holes in car bodywork to fit radio aerials.

Q-Max IIRC from the days we made chassis for radio projects ( holes for valve holders :( )


But the Op is trying to use a hole saw.
 
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If you are using machining quality stainless -angle rod etc there is no problem whatsoever drilling;filing etc
 
Stainless

Really the only way to get a decent cut, is as already suggested with a local machine shop, I did for the backing plates for my centre cleats. Just go on to the web & find a good local fabricator.

You can cut & drill SS but you need the right tools, including a drill stand, which will cost more than the one off material you have bought.

Good luck
 
I have used 2 mm sheet obtained for a song on e bay-small drilling no problem.For a one inch diameter hole a good quality hole saw might do the job but 0.5.. is very thin.
If you are using aluminium a bimetal hole saw will cut through it like butter.
I recently needed some 90 mm dia washers with a centre 40 mm cut out-cut both outer disc and inner hole no problem with bimetal hole saw on my bench pillar drill.
 
Hmm sounds like I'll have to outsource then :(
Not the end of the world, was going to have a boom gallows made (if I can afford it!) so I'll just ask them. It really did surprise me though, never had a problem punching holes in regular sheet metal. Perhaps I should get a stainless boat :D
 
http://www.ebay.co.uk/itm/Q-Max-She...t=UK_Hand_Tools_Equipment&hash=item53ebe873d0

for straight cuts in stainless, the thin angle grinder discs are very good.
For small holes, cobalt drills in a drill stand, or at least a new HSS drill is OK.
If the SS is already work hardened, a carbide drill as sold for tiles is often good, or a carbide burr in a dremel.

Although stainless is often a sod to drill, it files and grinds reasonably easily.

Good Luck and take care.
 
You say you haven't even dented it? Then the drill was not sharp enough! SS really needs good sharp bits, a slow speed and lubrication. If a drill bit blunts from excess speed and heat, the SS will work harden and the only way to continue is to change to a slightly larger drill so the shoulders can cut into unhardened material. However, as others have already said, at 0.5mm it should be possible to get a shop to punch a perfect hole through it if they have a flypress and suitable dies. Q-max cutters are great, but you still have to drill a centre hole first.

Rob.
 
You say you haven't even dented it? Then the drill was not sharp enough! SS really needs good sharp bits, a slow speed and lubrication. If a drill bit blunts from excess speed and heat, the SS will work harden and the only way to continue is to change to a slightly larger drill so the shoulders can cut into unhardened material. However, as others have already said, at 0.5mm it should be possible to get a shop to punch a perfect hole through it if they have a flypress and suitable dies. Q-max cutters are great, but you still have to drill a centre hole first.

Rob.
+1. Sharpness and very slow speeds are essential. And a lot of time and patience.
 
It does not take much time to drill a hole through 0.5mm

True. but I was assuming - maybe incorrectly - that the OP would abandon the hole saw approach and instead drill a lot of nearly contiguous small holes around the circumference, then angle his drill bit to join up said holes and - bingo - job done. Needs a bit of filing to tidy up but it's worked for me in the past!
 
The problem with drilling .5mm is the material will want to ride up the drill causing mis shaped holes with large burrs.
I've thought of a way which should work with a hole saw; Clamp the stainless between 2 bits of wood with say, G clamps, and then clamp the whole assembly to a solid surface (bench). The hole saw RPM for 1" I estimate around 150 RPM. Unless you have cutting fluid to hand, lubricate with oil, I've found hydraulic oil to be about right, but anything you got will help. I don't know much about hole saws, but any new reasonable quality will do, it just needs to be sharp.
When drilling stainless, it wants to be held firmly without any movement, either vibration, rotational and you don't want it to flex, hence the above method.
 
Last time I drilled stainless, I listen to the advice of very slow and good drill bit...

I did not centre punch I put some tape and X then used hand drill, I was amazed it just cut through like paper... Only good for small holes but I would do again..
 
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