Problem Drilling Stainless

[butterblum]

I am trying to drill multiple holes in my stainless kettle for some tri clamp fittings. I have tried using both a 1/8" HSS twist bit and the pilot bit on a hole saw, however I am making no headway on getting a pilot hole drilled. The material is only 1.2mm thick, I am using WD-40 as oil, I am applying pressure, and I am using low speed on my drill with the trigger only halfway pulled. It doesn't look like any progress has been made. How long should this take?

 

[day_trippr]

I think HSS is undergunned for drilling through stainless steel. I use a 3/16" cobalt twist bit for pilot holes then switched to a TiN coated step bit. The cobalt bit literally took less than a minute on my G1 kettles which are of similar wall thickness.

If you've been working at that hole for long you've likely hardened the spot beyond the ability of that bit to cut through. At the least, pick up a fresh bit and move your spot a bit. But I'd still recommend a cobalt bit, they seriously make short work of SS...

Cheers!

 

[Imburr]

I tried to drill stainless once with a step bit, what a mistake. Has anyone tried a dremmel?

 

[Transamguy77]

I used a 7/8” hole saw worked awesome, bought it at Home Depot for like $10 bucks.

 

[newtobrew1981]

I think HSS is undergunned for drilling through stainless steel. I use a 3/16" cobalt twist bit for pilot holes then switched to a TiN coated step bit. The cobalt bit literally took less than a minute on my G1 kettles which are of similar wall thickness.

If you've been working at that hole for long you've likely hardened the spot beyond the ability of that bit to cut through. At the least, pick up a fresh bit and move your spot a bit. But I'd still recommend a cobalt bit, they seriously make short work of SS...

Cheers!

Agreed titanium step bit is the way to go. Made short work of my kegels. Like tripper said your bit is dull or you've hardened your stainless. Get a new bit cutting fluid and go slow

 

[newtobrew1981]

Agreed titanium step bit is the way to go. Made short work of my kegels. Like tripper said your bit is dull or you've hardened your stainless. Get a new bit cutting fluid and go slow

I also bought one of those greenlee hole punches and I have to say the step bit was easier to use

 

[Bobby_M]

You need a new or freshly sharpened bit. Push as hard as you can without breaking the bit. That means at least 1/8" diameter. If the bit spins a few times without cutting, you've work hardened it.

 

[butterblum]

I've got a brand new cobalt bit and a can of WD-40. I guess we'll see how that goes.

 

[day_trippr]

Resist the temptation to attack the original spot. Move over a little...

Cheers!

 

[kh54s10]

I tried to drill stainless once with a step bit, what a mistake. Has anyone tried a dremmel?

I had to widen a hole once less than 1/16th inch wider. With the Dremel tool it took 2 stone grinding bits and over a half hour to get that small amount done........

4 holes with the step bit took only about 1 hour.

 

[hod_5517]

applying a lot of cutting fluids would help.

 

[MaxStout]

Try starting with a center punch. That creates a little divot that the drill bit can bite into. Then go easy--drill a few seconds, add more oil, drill a little more, add more oil, and so on. If the oil smokes you're letting it get too hot.

I've never had good luck with WD40 for drilling metal. I like a light machine oil, like 3-in-One. You can get that at any hardware store. Even a bit of motor oil works well.

 

[butterblum]

I tried a Dewalt cobalt bit and Tap Magic to no avail. Went very slowly, but won't drill very far.
I ordered a set of carbide-tipped masonry bits to try.

 

[SEndorf]

IMHO, the ONLY way I would attempt a hole in a stainless kettle, is with a Greenlee Punch

 

[schematix]

get a brand new cobalt bit with cutting oil (not wd-40), and let it rip at high speed (3000 RPM) and it will cut like buttah. the small bits can run high speed. it's the bit diameter ones you need to slow down for. hole saw or punch much better way to make the big big holes than a step bit.

 

[AZCoolerBrewer]

I know it’s basic, but do you have you drill going in the right direction?

 

[Bobby_M]

IMHO, the ONLY way I would attempt a hole in a stainless kettle, is with a Greenlee Punch

This is so misguided. In the time it takes to drill the hole for the mandrel bolt I would already be through the full size hole with a tungsten carbide hole saw.

Count the seconds... 8 seconds to make a 1-1/4 hole. Skip to 4:50 to see the start of drilling.

 

[SEndorf]

This is so misguided. In the time it takes to drill the hole for the mandrel bolt I would already be through the full size hole with a tungsten carbide hole saw.

Sorry you feel a punch is so "misguided"....
Apparently speed to complete this project is very important to you..

 

[aeviaanah]

Sorry you feel a punch is so "misguided"....
Apparently speed to complete this project is very important to you..

I’ve worked stainless the last 10 years and have never needed a punch for this sort of operation.

 

[schematix]

misguided is a strong word perhaps, but there is just a better tool for the job. faster, cheaper, cleaner cut and less error prone.

 

[day_trippr]

IMHO, the ONLY way I would attempt a hole in a stainless kettle, is with a Greenlee Punch

Being as you still need to drill the bolt hole to use the punch, you'd be in the exact same place as the OP until you got that accomplished.
fwiw, I did all of my kettle holes with a Greenlee punch - after drilling the bolt holes with the cobalt bit followed by the step bit...

Cheers!

 

[SEndorf]

Yes... And I've put plenty of holes in stainless kettles.
"Needed"... a punch? No...
Perhaps I should not have said "ONLY".. I was expressing my personal preference.
The bolt hole doesn't need to be clean. The finished result is no high RPM.. No heat... No burrs... No fragments.. No oil..
Not sure I agree with "cleaner" and less "error prone". A punch is a no brainer for those that don't have the tools or inclination to drill.

Not worth going to war over. "Misguided" just got me going.....
Drink on my friends...

 

[AZCoolerBrewer]

Greenlee punches are a baddass tool and should be used at every opportunity for that reason alone.

 

[cloudybrewer]

I ordered a set of carbide-tipped masonry bits to try.

NOOOOOOO!! DO NOT USE MASONRY BITS! When you get them, you'll see why.

 

[Soulshine2]

I tried a Dewalt cobalt bit and Tap Magic to no avail. Went very slowly, but won't drill very far.
I ordered a set of carbide-tipped masonry bits to try.

masonry bits are for masonry ,not ss. Stainless steel is so because of its high content of nickel. Not all SS is the same alloys either. You'll have to invest in cobalt . I have to say ,I've been in the construction trade over 26 yrs and the quality of a good drill bit has gone down incredibly. I can remember using drill bits like forever then for some reason the bits you buy today can barely drill one hole before they break or just dull out. I've sharpened drill bits by hand on a bench grinder that cut better/faster/more times than a brand new one. Its sad

 

[kh54s10]

Yes... And I've put plenty of holes in stainless kettles.
"Needed"... a punch? No...
Perhaps I should not have said "ONLY".. I was expressing my personal preference.
The bolt hole doesn't need to be clean. The finished result is no high RPM.. No heat... No burrs... No fragments.. No oil..
Not sure I agree with "cleaner" and less "error prone". A punch is a no brainer for those that don't have the tools or inclination to drill.

Not worth going to war over. "Misguided" just got me going.....
Drink on my friends...

Greenlee punches are a baddass tool and should be used at every opportunity for that reason alone.

Unless I have read wrong, you need to drill a hole for the mandrel on the punch. The OP cannot get a hole drilled at all!!!! How is a punch going to work in this case???

I agree that the masonry bits are not going to work.

 

[Soulshine2]

With a sharp pointed punch and a good solid hammer strike to it , you can put a nice single dent in the CURVED ss surface ,the bit wont tend to wander off the target.
I know in the past I've had to drill into ss but it was on a job and we had an endless supply of industrial bits. Its work.

 

[AZCoolerBrewer]

Unless I have read wrong, you need to drill a hole for the mandrel on the punch. The OP cannot get a hole drilled at all!!!! How is a punch going to work in this case???

I agree that the masonry bits are not going to work.

I’m not necessarily advocating that the OP use a Greenlee punch, but if he/she can then they should because those things are cool.

 

[butterblum]

I have a carbide-tipped hole saw for the Tri-clamp hole. I just need help with the pilot hole so that I can use the hole saw.
The cobalt bit I bought sucked.

 

[lschiavo]

Slow speed drill and lots of pressure.

 

[butterblum]

Both of those tips were followed, as well as using plenty of Tap Magic.
There are threads out there about Concord pots using a different grade of stainless - I do not have a Concord, but I wonder if it is similar situation.

 

[ProblemChild]

Use a wood block and a spring-loaded center-punch to locate the hole. back the inside of the pot with the block and mark the outside with the punch. This will allow the cutting edge of a small bit like a 1/8" bit to grab and keep the bit from walking. this is not necessary, but makes sure your hole location is exactly where you want it.

Pulse the drill to get started - do not wind it out. If the steel heats, it will work harden (if pot is 18-8 anyway, 304 does not work harden) and be harder to drill. Ensure you keep the wood backing on the inside to allow for application of some pressure. (Not a ton - you are not trying to shove the bit through the metal). Not only that, but if you go through too quickly, the metal will grab the bit and climb, making a nasty hole.

Step bits will work well at this point, just remember that coating the step drill with a light coat of cutting fluid (or any oil for that matter) will help.

If you can back the inside of the pot safely when drilling, it will be much easier. Safety is always a concern. Use proper PPE. Getting a metal shaving in your eye is never fun.... Running a drill bit into your hand also kind of sucks. Have done both.

 

[butterblum]

I finally found a way to get through this stainless.
I bought this set of bits for a pilot hole:
https://www.homedepot.com/p/Bosch-M...d-Metal-and-Concrete-5-Piece-MP500T/301372988
And I used this hole saw to cut the 32mm hole:
https://www.amazon.com/dp/B01I416TR4/?tag=skimlinks_replacement-20
I had to go at like 60rpm with the bit for the pilot hole. I used Tap Magic and it took a solid 3-5 minutes to get through. I never had a spiral of material, only little flakes. The carbide hole saw had no issues.

 

[hankinsonk]

Just wanted to share that a Milwaukee 1/8 in. Cobalt Red Helix Twist Drill Bit from HD cut my pilot hole in my MegaPot 1.2 with some EVOO to lubricate. Took a little while with steady pressure, pausing to redip in EVOO and continuing. Cut my 41 mm hole with a tungsten carbide hole saw, and a little EVOO, from @Bobby_M for my new TRUE Weldless 1.5" TC Triclamp Bulkhead. Cheers!