Drilling a pilot hole in stainless steel pots

[yveei]

This is to thank members of the forum and to help others out...

I've been struggling over the past few days to drill a pilot hole into my 70L stainless steel pot. I've watched YouTube videos, read many posts on this forum, and done a lot of Googling.

3 broken drill bits later, here is (IMO) the foolproof solution...

1. Buy a decent cobalt drill bit
2. Use a centre punch to mark where the centre of your hole will go
3. Add a little lubricant to where you'll be drilling - I used some general purpose spray lubricant
4. The secret... drill quickly!
   A lot of advice says to go slowly and apply pressure. This is correct for cutting large holes, but for the pilot hole speed is the key!
   By fast I mean 900rpm - not 90rpm as I was doing
5. Do apply pressure but you don't need to go wild.
6. Every 30 - 60 seconds, dip the drill bit in some water. I never once heard the water sizzle so I knew the speed was fine
7. Be patient but persistent, you will drill that hole!

That's it.

The battery's dead on my drill so I'll be using a step bit tomorrow to widen the pilot holes.

But thank you to this forum for all the advice and getting me this far in my brewing adventure!

 

[UncleD]

Agreed. Good drill bits designed for stainless steel, lubricant, and the correct speed/pressure are key. Also being patient and pausing to allow the bit to cool in between drill cycles.

 

[day_trippr]

One thing many folks don't do is to put a decent dent in the pot with a punch. I like to give it a good enough whack to allow a decent puddle of oil to sit in the dent. Along with a cobalt bit turned at around 1-2 rps it makes holing a kettle easy as pie.

3/16" pilot hole. Curlies are A Good Thing

Widened to 5/16" with a step bit. Note the dent is pretty much removed already.

Finished with a Greenlee 13/16 punch. Dent gone, bulkhead sealed perfectly.

The whole thing took less than five minutes. No tools were harmed

Cheers!

 

[Bobby_M]

1. Every 30 - 60 seconds, dip the drill bit in some water. I never once heard the water sizzle so I knew the speed was fine
2. Be patient but persistent, you will drill that hole!

I'm a little confused. It takes me literally 5 seconds to drill a 3/16" or 1/4" pilot hole. I go about 200 RPM and put about 100 LBS of force on the bit. If you're trying to go with a smaller bit, like 1/8", you'll want to lighten up the pressure a bit but you can save the bit by inserting into the drill as far as the bit will go. The biggest mistake people make drilling stainless is spinning the bit without cutting. Stainless almost instantly work hardens and you have to be simultaneously removing a sliver of work hardened material on every revolution.

 

[yveei]

I'm a little confused. It takes me literally 5 seconds to drill a 3/16" or 1/4" pilot hole. I go about 200 RPM and put about 100 LBS of force on the bit. If you're trying to go with a smaller bit, like 1/8", you'll want to lighten up the pressure a bit but you can save the bit by inserting into the drill as far as the bit will go. The biggest mistake people make drilling stainless is spinning the bit without cutting. Stainless almost instantly work hardens and you have to be simultaneously removing a sliver of work hardened material on every revolution.

Maybe I wasn't putting enough pressure on. I'd lost two bits the night before so I was hesitant to apply too much pressure this time round.
Or maybe your drill bit is just a lot better than mine!

Try as I might, I couldn't get that pilot hole done any faster than about 5 - 10 minutes.

Did you use a handheld drill or a drill press, Bobby-M, out of interest?

 

[day_trippr]

Holing a pot on a press would be way more challenging that just using a good strong cordless drill. I have a full size press and it would take a jig to keep the pot from skidding away from the bit.

That 3/16" pilot hole took about 15 seconds using a Dewalt 20v drill, and in spite of turning the bit really slowly. The curlies show the bit was working nicely...

Cheers!