# Drilling Stainless Steel



## Dicko72 (20/11/13)

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 (20/11/13)

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


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## Jono_w (20/11/13)

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.


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## jaypes (20/11/13)

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


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## Dicko72 (20/11/13)

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 (20/11/13)

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.


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## Thefatdoghead (20/11/13)

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.


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## Ducatiboy stu (20/11/13)

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.


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## Dicko72 (20/11/13)

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

Fat Bastard 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 (20/11/13)

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 bastard file to file away the work hardened bits. Take a bit of elbow grease but you can do it on your own.


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## djar007 (20/11/13)

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.


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## Dicko72 (20/11/13)

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 (20/11/13)

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.


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## Dicko72 (20/11/13)

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

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## hellbent (21/11/13)

D!CKO said:


> Damn it. I could have put the 50 bucks worth of bits towards one of those bad boys..
> 
> Sent from my HTC One using Tapatalk


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


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## djar007 (21/11/13)

Hindsight is a wonderful thing.


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## gap (21/11/13)

D!CKO said:


> Damn it. I could have put the 50 bucks worth of bits towards one of those bad boys..
> 
> Sent from my HTC One using Tapatalk


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

Regards

Graeme


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## maxim0200 (21/11/13)

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.


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## wide eyed and legless (21/11/13)

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.


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## sp0rk (21/11/13)

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


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## seifer (21/11/13)

Step Drill bit, you'll never look back. Low and slow with a bit of cutting oil!


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## JaseH (21/11/13)

Seifer said:


> Step Drill bit, you'll never look back. Low and slow with a bit of cutting oil!


Stepped drill bit was fckn useless on my keggles - managed one hole out of it before it was stuffed and wouldn't do any more. The best bits for the job are the tungsten carbide tipped hole saws that Keg King have. I've drilled a dozen holes through heavy stainless kegs with them, they cut like butter and are only about $10-$16 each!


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## sp0rk (21/11/13)

Frothie said:


> Stepped drill bit was fckn useless on my keggles - managed one hole out of it before it was stuffed and wouldn't do any more. The best bits for the job are the tungsten carbide tipped hole saws that Keg King have. I've drilled a dozen holes through heavy stainless kegs with them, they cut like butter and are only about $10-$16 each!


Are you using cutting oil/fluid, slow speed and applying pressure?


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## JaseH (21/11/13)

sp0rk said:


> Are you using cutting oil/fluid, slow speed and applying pressure?


Yeah, but the step bit material is just too unforgiving for stainless steel using a hand drill, I got one hole ok but a couple of slip ups with drill pressure or drill speed - the drill stops biting into the steel and its all over, the bit edge is rooted. The tungsten carbide hole saws just bite in and chew through stainless all day long and are cheaper!


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## maldridge (21/11/13)

Seeing this thread brings back some bad memories.

A couple of months ago I wanted to install some thermometers into my 70L SS pots. To do so required holes drilled into the pots.

I bought a step drill bit from bunnings, a super cheap one, thought it'd do the job. Took it home and had a crack with a bit of WD-40 and a low speed. Nothing. Not a dent. Absolutely no effect what so ever.

I took that step bit back to bunnings and returned it for a more expensive one. The bloke said to try using a punch before or at least putting some tape down first, so the bit wouldn't slip. Get home, have another go. Nothing. This time you could see the tiniest spec where I had attempted to drill a hole.

Took that bit back to bunnings for a refund. Went to Keg King to see what they had. Turns out they had some tungsten carbine hole saws on sale (listed above) which are for this exact purpose. The bloke there said they use them and it should work without any problems. AWESOME. Took it home. The pilot bit on the saw didn't make a dent. How the crap could I drill my hole if I couldn't even get a pilot hole drilled. Honestly had never been so frustrated.

I ended up taking the drill bit back and got them to hydraulically punch some holes in my pots for me, for a very reasonable price of $15 per hole.

Now I need some more holes for a sight glass, which is why I tried to buy my own bit, as I knew I'd want more holes in the future. But I really can not be fucked to go through all that again. I'll probably end up taking my pot to KK for a second time.


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## JaseH (21/11/13)

maldridge said:


> Took that bit back to bunnings for a refund. Went to Keg King to see what they had. Turns out they had some tungsten carbine hole saws on sale (listed above) which are for this exact purpose. The bloke there said they use them and it should work without any problems. AWESOME. Took it home. The pilot bit on the saw didn't make a dent. How the crap could I drill my hole if I couldn't even get a pilot hole drilled. Honestly had never been so frustrated.


Actually, the pilot bits on these are a weak point. Trick is to use a center punch to mark the center - then use a normal sharp drill bit ~4-5mm to drill a pilot hole, then use the TCT hole saw.


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## maldridge (21/11/13)

I had no luck using a hole punch at all. I just felt like because it was a pot and was hollow, when I wacked the punch it just wasn't solid enough to dent the steel.


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## QldKev (21/11/13)

I've drilled many holes into kegs using my cheap ebay stepped dill bits. Even with a stepped drill bit you still should use a pilot hole. Really slow speed, medium pressure and heaps of lube. If the job starts to get hot and the lube smokes, stop and let it cool down.


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## Wortgames (21/11/13)

While we're sharing stainless drilling tips, don't be tempted to 'pulse' your pressure - press hard and drill for a few seconds, then stop drilling and let it all cool down.

Backing off the pressure just means less cutting and more heating.


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## Yob (21/11/13)

$15 a hole????

WTF?

Bring it round mine, will do it for free


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## robbo5253 (21/11/13)

QldKev said:


> I've drilled many holes into kegs using my cheap ebay stepped dill bits. Even with a stepped drill bit you still should use a pilot hole. Really slow speed, medium pressure and heaps of lube. If the job starts to get hot and the lube smokes, stop and let it cool down.



Kev,

Did you use the STep bit for the Uxcell elements or just a normal drill bit? Looking to buy a few in the coming weeks and not sure what drill bits I will need to install them

Cheers

Robbo


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## QldKev (21/11/13)

robbo5253 said:


> Kev,
> Did you use the STep bit for the Uxcell elements or just a normal drill bit? Looking to buy a few in the coming weeks and not sure what drill bits I will need to install them
> 
> Cheers
> Robbo



For the Uxcell elements I used a normal HSS twist drill bit, but there is no reason you could not use the stepped drill bit for it.

For $11 posted those ebay step drill bits (type 1) are a bargain, but they took a month to get here. Even the Bunnings ones should be ok if you pre drill a pilot hole and don't get them hot. Use plenty of CRC/Diesel/Engine oil to keep it lubed and cool.

Ultimately it doesn't matter which one you get, HSS twist, stepped or hole-saw, if you spin the drill fast and overheat the job you will make life hard for yourself. Even if you use WortGames idea, drill for a sec, and go pour a beer. It may take 30mins to drill the hole you will get there without damaging the drills or the job.


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## Mardoo (29/11/13)

I'm putting in a big thumbs up for the godblessed sheet metal punch. Hell, putting that hole in my kettle was eeeeeaaaaasy. Literally the hardest part of cutting the hole in my pot was drilling the guide hole for the center bolt on the punch. I was totally astonished how quick and simple that was, with no burrs etc. Wow. As far as I can tell there's no chance of work hardening either, but then I'm no metallurgist. But really, if you want a simple solution for getting the hole in that pot, check these out:

http://www.pretooling.com.au/products/sheet-metal-punches-3-point.html

(No affiliation etc...) There are plenty of sources here in Oz and on eBay.


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