Drilling Stainless Steel

[Dicko72]

Hi Folks,

Started drilling some 16mm holes in my stainless stock pot tonight.

All went well except for hole number 4. The last hole!

When drilling the last hole I was the hole saw must have been too hot and it flattened the teeth.

So I went out and bought a cobalt 16mm hole saw which at $25 wasnt cheap.

Especially as it lasted about 5 seconds and the same thing happened!

Reading stuff online it sounds like the steel is now work hardened.

Does anyone have any ideas?

Thanks in advance.


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[Dylo]

Pick a new spot. Gotta drill as slow as possible and use some cutting fluid too. Work hardened steel is impossible

 

[Jono_w]

Definitely work hardened mate. Not much you can do now I have used a die grinder with a burring bit to grind out holes like this before.
As Dylo said, slow and plenty of cutting fluid. Even wd40 works for me if I have nothing else.

 

[jaypes]

You should have used a cutting compound paste like trefolex and always go in short bursts and not flat out with the drill.

You could probably try a stepped drill bit, unfortunately stainless is pretty hard to begin with and it might bung the bit as well.

Your last option could be a professional press punch from a fabricator, it might be also worth them tigging the hole you have made and try to drill a new one

 

[Dicko72]

Unfortunately I can't pick another spot as I'm committed now! I did use cutting oil just a tad ambitious on the last home.... Sigh..

So no holesaw will cut it now?
May have to seek professional help!

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[Fat Bastard]

Buy a cheap step drill and use that, very slowly, those Ozito drills that are reccomended for running mills are ideal for drilling stainless. If you're stuck and in Sydney, I have a hydraulic punch that you can borrow to get you out of trouble.

 

[Thefatdoghead]

Cut a smaller hole where it isnt hardened then die grind the hardened shit out. Either that or go to a sheet metal joint and pay $50 for them to cut it with a punch or a plasma.

 

[Ducatiboy stu]

Stainless csn be a real PITA as the more you drill the hotter it gets which makes it harder which makes the drill bit hotter which makes it harder which makes the drill bit.....once its work hard your fucked

You need a good cutting compound/oil and drill it slow and steady. Diesel is also good as it helps lubricate.

I also hate drilling brass because the bit chatters if not done correctly.

 

[Dicko72]

Holy shit. I had no idea that this would be such an issue...

Fat ******* I may take you up on that offer mate if I get stuck thank you.

I'll call a few metal fabricators tomorrow. I'm in lower blue mountains there must be somebody nearby who can do the job for me before I **** it up more!

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[pk.sax]

Well, use a smaller sized holesaw to cut a just smaller hole inside the hardened one (using the centre hole you've already drilled), you'd then need a grinder or a round ******* file to file away the work hardened bits. Take a bit of elbow grease but you can do it on your own.

 

[djar007]

As Jonathan said. Dremel and a bur. You will already have a pilot and an outline. A bur will chew it out and neat with a steady hand.

 

[Dicko72]

Thanks everyone for the quick responses. Have to get this sorted for the weekend. Don't want a drought over the Xmas period!

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[law-of-ohms]

I have a plasma cutter, best $249 on ebay ever! lol. I just drilled a 16mm hole with my hole saw, no cutting fluid, worked fine.

 

[Dicko72]

Damn it. I could have put the 50 bucks worth of bits towards one of those bad boys..

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[hellbent]

Damn it. I could have put the 50 bucks worth of bits towards one of those bad boys..

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You could also have used the $50 to get a professional to drill it for you.

 

[djar007]

Hindsight is a wonderful thing.

 

[gap]

Damn it. I could have put the 50 bucks worth of bits towards one of those bad boys..

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Try these guys in Valley Heights http://www.stainlesssteelworx.com.au/

Regards

Graeme

 

[maxim0200]

Forgive me if im wrong but would it be possible to un work harden it by heating it up with a blowtorch and then let it cool verry slowly, pack it with hot sand or cover with fire resistant blankets?

Edit to add:
Also your drillbits shouldnt be f'd, sharpen them on a bench grinder.

 

[wide eyed and legless]

I doubt he could achieve the temperature needed to anneal the stainless and if he did I believe the chromium and carbon separate the best lubricant if your cutting stainless is kerosene, I would take up FB's offer and punch it out.

 

[sp0rk]

I think the best coolant is the free samples that come from unist.com.au