# Drilling stainless



## nitro71 (Sep 17, 2009)

I smoked two 1 1/8" hole saws today and two pilot bits the day before on some stainless cans I have. Is there a unibit that can hold up to them that will let me get a slug buster on it. Will the slug buster break also? I got the holes in for now but will be putting another 2-4 in them soon. I used some cutting wax. It kinda helped I guess.


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## RIVETER (Sep 26, 2009)

nitro71 said:


> I smoked two 1 1/8" hole saws today and two pilot bits the day before on some stainless cans I have. Is there a unibit that can hold up to them that will let me get a slug buster on it. Will the slug buster break also? I got the holes in for now but will be putting another 2-4 in them soon. I used some cutting wax. It kinda helped I guess.


I have mentioned this before but I had good luck stuffing the hole saw with a rag and soaking the rag with cutting oil. I drilled a bunch of 3/16 stainless successfully.


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## nitro71 (Sep 17, 2009)

I'll try it next time I'm cutting it. Maybe I just need to get a unibit or hole saw at a machine shop supply place instead of the supply house.


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## RIVETER (Sep 26, 2009)

nitro71 said:


> I'll try it next time I'm cutting it. Maybe I just need to get a unibit or hole saw at a machine shop supply place instead of the supply house.


It wouldn't hurt to have a unibit as a back up but the trick is to have enough forward pressure for the sharp teeth to create the friction for cutting of the metal without pushing too hard and bending the metal.


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## mattsilkwood (Sep 21, 2008)

Slow speed, high pressure. 
I have used a regular slugbuster on stainless, If it's just a few it should be alright but if it's a lot of holes I would probably get a ko for stainless.

I also learned the hard way to keep the drawstud off the edge of the hole. It took me an hour with a file to clean the threads up on it.


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## Lone Crapshooter (Nov 8, 2008)

Fastenal has some stuff that looks like green shaving cream it works well. 
Also DO NOT CENTER PUNCH the work use a split center bit. They don't walk like regular bits do. Low speeds and lots of pressure and DO NOT LET THE BITS SPIN IN THE HOLE WITHOUT PRESSURE it work hardens the stainless.


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## Wingnut (Jan 31, 2010)

We use these

And go half speed, push as hard as you can, without bending your can.

When you notice its not cutting, stop and let your stainless cool down. put some of your paste on your hole, let it set until it turns back to paste.


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## nitro71 (Sep 17, 2009)

This is going to help a lot. I thought maybe I was tempering it by letting the stainless get cool. I actually had molten pieces of it coming off when I was using my unibit on it.


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## Big John (May 23, 2010)

I agree with slow-speed high pressure. I've found that to be better when drilling just about any metal. Even when you don't have the work-hardening problem like with stainless, slower speed seems to save the bits.

A lot of guys say don't use cutting fluid with stainless. My thinking is this: Fluid might cause the cutting tips to slip and be less effective, but it keeps everything a lot cooler. 
-When the drill-bits/saws are cooler, they keep their edge longer.
-When the stainless is cool, it doesn't temper and work-harden from the heat. 

I think both of those make hole-cutting easier.

-John


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## RIVETER (Sep 26, 2009)

nitro71 said:


> This is going to help a lot. I thought maybe I was tempering it by letting the stainless get cool. I actually had molten pieces of it coming off when I was using my unibit on it.


Wow!!!What a good time to be VERY deep in discussing what is happening. A sharp bit creates heat, which in turn causes the electrons to absorb the heat/energy and move farther away from the nucleus and thereby creating a lesser hold on those electrons, and the metal just comes apart. I think that's it.


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## Lone Crapshooter (Nov 8, 2008)

Don't use lubricating oil for cutting oil. It will slow the cutting process down because it is lubricating. 
You would not use cutting oil in your car would you.


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## qckrun (May 18, 2009)

If you punching a bunch of holes get a stainless steel shaft. We had about 50 holes to punch most 5", and we broke 3 steel shafts. Last hole was our 3rd break.

To punch it out for the die, we just got a bunch of cheap 1"holesaws and went to town with cutting oil spray out of a can.


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## MDShunk (Jan 7, 2007)

Very low speed, lots of pressure. That's 90% of the battle when dealing with stainless. You want really nice chips, coming out on a continual basis. Once you start to spin without generating chips, you're effed.


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## TOOL_5150 (Aug 27, 2007)

I think I heard it once before on here, to use vinegar? I dunno.. maybe i am just off kilter.

~Matt


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## nitro71 (Sep 17, 2009)

MDShunk said:


> Very low speed, lots of pressure. That's 90% of the battle when dealing with stainless. You want really nice chips, coming out on a continual basis. Once you start to spin without generating chips, you're effed.


That's exactly what happened. Thought I was going to start a fire in the can,


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## jwjrw (Jan 14, 2010)

We recently had a thread on this. Lots of good ideas in it. Last job I did I used wrenches and slug busters till I bought carbide hole saws. They worked better than any other cutting method I tried. I'm gonna try the vinegar next time.


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## Stardrill (Mar 8, 2008)

I'm told by guys that work with stainless everyday that the best fluid for drilling is water.


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## kinglew (Mar 16, 2008)

*stainless drilling*

small starter bit step up to larger size in steps .slow speed drilling on off on on off.this clears the chips as drilling on off works great for me do lots of stainless. also good lube buy at machine shop supply


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## cobra50 (Aug 12, 2009)

Anyone tried this greenlee product
http://www.toolup.com/greenlee/660.html


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## sparky970 (Mar 19, 2008)

cobra50 said:


> Anyone tried this greenlee product
> http://www.toolup.com/greenlee/660.html


Not worth the money, I'd buy Lenox.


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## Wiredude (May 14, 2010)

We recently did some work where we had to punch out some stainless N4X boxes. We ended up buying a kit of carbide tipped hole-cutters from Magbit http://www.magbit.com/saws_626_tungsten_carbide_tipped_hole_cutters.php . The guys on the job said they worked wonderfully, and if I remember the kit (which included 1/2, 3/4, & 1" KO sizes) was around $100


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## Podagrower (Mar 16, 2008)

Someone I used to work with suggested water with sugar in it. I laughed, until I tried it. Now, I look for it whenever I need to drill stainless. High sugared soft drinks work quite well, though obviously not in energized panels.

Using a unibit in stainless is a death sentence for the unibit IMHO, you cant dissipate the heat fast enough.

Regular knockout punches will have their lives shortened (sometimes dramatically) when used with stainless.


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## kevmanTA (Jul 20, 2010)

Cheap hole saws, and a set of Irwin drill bits work for me.. Just drill slow, and steady, don't let it get hot. I use a coolant I stole from a machine shop, I think it's a thin tapping fluid.


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## BuzzKill (Oct 27, 2008)

TOOL_5150 said:


> I think I heard it once before on here, to use vinegar? I dunno.. maybe i am just off kilter.
> 
> ~Matt


yeah there was a thread about using vinegar on stainless on here over the summer maybe. :thumbsup:


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## heavyduty73 (Jan 11, 2008)

Anyone ever try buttermilk.


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## Stan B. (Jul 25, 2008)

Cutting oil is like Kryptonite to electricians.


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## gold (Feb 15, 2008)

Hole saws are sloppy IMO Get the stainless dies. Drill a small hole first then bigger then bigger etc. I drill through a wet sponge to save my bits. Keeps the bit and the box cool.


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## Thedroid (Dec 6, 2010)

I like to start small and then work my way up with the KO's. I use Tap Magic cutting fluid to extend the life of my drill bits, and I use good drill bits. We have several Morse hole saw kits, and I've never thought twice about using them. Drill 3/8" hole use 1/2" KO, then go to whatever the finished size is.


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## Jupe Blue (Aug 18, 2008)

Stardrill said:


> I'm told by guys that work with stainless everyday that the best fluid for drilling is water.


I agree, water works. I worked on a retrofit of a lift bridge with lots and lots of stainless disconnects. The apprentice (me) dribbled a small stream of water while the JW drilled. Worked like a charm.


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## millertimo (Jan 5, 2011)

use these....i sell these for about 70-90 bucks a set(ideal #36-311)...you can add other sizes to complete a kit.....never had one returned yet.

http://www.idealindustries.com/media/pdfs/products/brochures/p-2842_tko_brochure.pdf


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## Jlarson (Jun 28, 2009)

I never really do anything special when drilling stainless. I don't mess around with cutting fluid (Unless I'm using a drill press doing an ungodly # of holes), or adjusting the speed of the drill either.

I will say though my favorite way to make big knockouts in stainless is just to break out the plasma torch, obviously this technique is limited to new work though.


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## pugz134 (Nov 8, 2010)

I got this tip from an old millwright:

Pulse the drill motor. Use some oil. Don't press hard. Never let the tip of the bit heat up. Never let the hole saw heat up. You can use a standard lenox hole saw off the shelf. nothing special. I drilled 80 3/4 holes in the top of stainless control cabinets with only 2 pilot bits and 2 hole saws. No need for special tools. Try it out. It works.

When you knock out stainless, pump the knockout once or twice and then let it rest. The metal will give a little. Then pump it a few more times. Repeat this process. It is a little slow, but faster than stepping up knockout sizes.


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## macmikeman (Jan 23, 2007)

Jlarson said:


> I never really do anything special when drilling stainless. I don't mess around with cutting fluid (Unless I'm using a drill press doing an ungodly # of holes), or adjusting the speed of the drill either.
> 
> I will say though my favorite way to make big knockouts in stainless is just to break out the plasma torch, obviously this technique is limited to new work though.


That's what I was going to post. My plasma cutter - I've made box cutouts in stainless backsplashes with it before as well as holes.


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## Lsparky (Sep 28, 2010)

I was doing some work in a machine shop and had to holesaw some KOs in stainless......the machinest came over and said "why don't you do it the easy way" and I said how is that? He gave me a small can of cutting oil made especially for tapping and cutting stainless. I tried it and it went through the stainless like it was hot butter....that was 20 years ago. No, I don't remember the name....just an old sparky remembering the good old days.


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## mrmike (Dec 10, 2010)

pugz134 said:


> I got this tip from an old millwright:
> 
> Pulse the drill motor. Use some oil. Don't press hard. Never let the tip of the bit heat up. Never let the hole saw heat up. You can use a standard lenox hole saw off the shelf. nothing special. I drilled 80 3/4 holes in the top of stainless control cabinets with only 2 pilot bits and 2 hole saws. No need for special tools. Try it out. It works.
> 
> When you knock out stainless, pump the knockout once or twice and then let it rest. The metal will give a little. Then pump it a few more times. Repeat this process. It is a little slow, but faster than stepping up knockout sizes.


 

This is the best advice here. I had learned the same thing from a millwright in the plant I used to work in. He was drilling into a big I beam.... By "pulsing" the motor, you go back & forth with your speed-almost shutting it off & back up again. This works because it doesn't heat up & the bit "grabs" the metal.........Try it when drilling into any hard drilling metal...........


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## danhasenauer (Jun 10, 2009)

Lone Crapshooter said:


> Fastenal has some stuff that looks like green shaving cream it works well.


It's called "Anchor Lube", works OK. My first 10 years in the trade was at a large chemical manufacturer, everything was stainless. I learned "Low speed, High feed" (push kinda hard) was the way to go. If your chips start coming off blue in color, the RPM's are too high.


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