Advice for drilling holes in stainless steel pots

[welly2]

I'm currently building my HLT and have got everything together now, just need to drill some holes for the tap and heating elements. Haven't worked with steel much before, certainly haven't drilled holes in it. I've got: centre punch, HSS stepped drill bit, cutting fluid. Any tips on actually doing the job itself? I've got 12mm and 32mm holes to drill!

Thanks!

 

[jonnir]

Just make sure they are new drill bits and take your time drilling the hole. Be sure to use plenty of cutting fluid and you'll be well on your way mate!

 

[pk.sax]

Use low speed on the drill.

Those step bits will easily work harden the hole if you drill too fast or don't use the cutting fluid. Give it rests if you think its heating up too much - both steel and drill bit.
Have a round file handy to ream the hole if you end up hardening it at any stage. That takes away the hardened bit and lets you carry on.

Patience.

 

[Yob]

Very, very slow is better, lots of fluid, if the bit heats up, allow to cool and start again.

I found those step bits to be troublesome, tct how saw bits FTW

 

[welly2]

Cook, thanks for the advice. The step bit is for the 12mm hole, got one of those 32mm tungsten tipped hole saws on the way for the bigger one. Slowly it is then!

 

[huez]

put it in a drill press if you have access to one big enough. Drill a smallish pilot hole to, to get things started. Hate drilling big holes in metal, hold on tight cause you will know about it if that drill bit grabs!

 

[Online Brewing Supplies]

Get someone else to do it when they have been drinken ,saves all the work and you have someone to blame.
Honestly it aint too bad once you done ten holes. Experience is the key.

 

[neo__04]

i found it fairly easy.

Drill slow is the key. I didnt use cutting fluid.

I got a new drill bit from bunnings, sutton tools was the brand, fairly flat point on it, says on the packet designed for stainless steel.
I drill a 3 mm pilot hole and then use step drills to open it up to size.
Probably done 10-15 holes now with the same technique.

Generally stainless is drill slow, and you need a bit of pressure. But just be careful with the pressure on very small drill bits.

 

[TheWiggman]

Strongly agree with the above. Get a new 3 or 5mm bit and drill a pilot hole first.
Set your drill on the slowest setting (1) if it has one to avoid burning it out.
Spray the bit and surface with WD40 or cutting fluid if you have it.
Drill slowly and apply a lot of pressure. When it starts to smoke up, stop and give it another spray. Continue and repeat.
Give the holes a file afterwards and carefully sand them with about 120 grit later to avoid cutting the silicone washers when you do your fittings up.
Keep the kids away in case you stuff up so you don't have to explain to your wife later about where they learnt 4 letter words.

 

[welly2]

Bugger me, I'm hardly making a mark in this bloody thing. :angry:

 

[welly2]

Well, been at this for about 10 minutes and I'm getting nowhere. I'm using these drill bits - http://www.bunnings.com.au/craftright-3-piece-speed-step-drill-bit-set-_p6360137 - which I realise aren't the best in the world but I'd have thought even if only for one use I could get through this stupid pot and then chuck them away.

Either my drill bits are shit (fairly likely but still), I'm not putting down enough pressure (feels like I am), I've not been at it long enough or something else that I can't figure out.

This is 10 minutes work:

 

[welly2]

Bah. That drill bit is definitely not up to the task. I'm going to have to get myself to Bunnings to get something else and/or pick up a 15mm (I incorrectly said 12mm above) tungsten carbide drill bit from keg king, if they do them.

 

[TidalPete]

Those step drills are best used for drilling in mild steel thin sheet (read fridges & freezers) so not surprised at your pic.
As mentioned earlier you will need to drill a 3mm or so pilot hole first to make things easier. Sutton is a good brand & not Chinese shit (apologising for racist remark ).
Very hard to go wrong with a decent brand of hole saw like Sutton or similar when going slowly at low speed on a 2-speed drill & using some sort of lubrication like sewing machine oil or lathe coolant.
If you see smoke then you are burning the drill & hardening your stainless so stop & cool things down.
Good luck with it welly2.

 

[TidalPete]

PS --- If I wanted to get a decent carbide-tipped drill or hole saw then Bunnings or KK are about the last places I'd select. :lol:

Having re-read this thread & noted that The Big Green shed does indeed sell quality (Sutton & probably other) stuff I'm humbly doing this edit. B)

 

[welly2]

PS --- If I wanted to get a decent carbide-tipped drill or hole saw then Bunnings or KK are about the last places I'd select. :lol:

Ha, I'm sure you're right I'll keep looking.

 

[booargy]

To fix that I change the angle of the cutting edges. For coolant put the hose on it.

 

[TheWiggman]

If the bit isn't cutting after the first 5 secs (I.e small shards of metal flicking off) then all you're doing is rubbing the metal against each other which heats it up. This will blunt the edge of the bit, work harden the stainless in the process and make your bit useless and at the same time make your stainless harder to cut.
You need a lot of pressure, around 40kg, to drill it well.
And yes an Aussie or NZ made sutton bit won't let you down unless you don't keep the bit cool or don't put enough weight on it.

 

[welly2]

Well, chuffing hell. It's amazing what you can do with the right tool (a Sutton HSS cobalt bit).

It literally went through it like butter and that was enough to get my cheap and nasty Bunnings step bit to open up the hole big enough. I now have an HTL.

 

[wide eyed and legless]

A good tip I have read and tried is to grind your centre punch into a pyramid shape and keep centre punching the hole, the drill bit has something to bite into and cut, and you will only need a HSS drill bit.

 

[Online Brewing Supplies]

Well, chuffing hell. It's amazing what you can do with the right tool (a Sutton HSS cobalt bit).

It literally went through it like butter and that was enough to get my cheap and nasty Bunnings step bit to open up the hole big enough. I now have an HTL.

Yes a bit of quality goes a long way to getting the job done, remember that when you buy brewing gear that costs a few dollars more
Nev