How do I drill through hard metal?

[sjoerik]

Recommend drill for stainless steel (they have a blunter angle on the drill so a larger area engages and are made of HSS-Co steel)

https://www.jula.se/catalog/verktyg...ch-borrset/borr-for-metall/metallborr-181728/

To get a mark/"körnslag," you can first run the drill in reverse at low speed. If you use proper körnslag as on regular steel, the stainless steel gets compressed, making it even harder/more difficult to drill. The same thing unfortunately applies if you use a blunt drill and compensate with too much pressure on the drill...

Plenty of cutting fluid or "Pudding"=cutting paste
Example:
https://verktygsboden.se/maskin-tek...arvatskor-oljor/gangpasta-trefoflex-rostfritt

 

[Workingclasshero]

Cutting fluid or at least some form of oil for lubrication. High pressure on the drill, low speed. And a good drill.
If you can access it with a large one-hand clamp, you can use it to apply pressure to the drill. Very difficult to apply enough pressure if you can't push downward.
For larger holes, it can be good to drill a smaller one first.

Hi
You should never press hard, never!
Start with a smaller drill and continue with larger ones.
Suitable steps can be 4mm, 8mm, 12mm.
Use oil or cutting fluid.
The larger the drill, the lower the speed.
Ensure that your drill bits have sharp edges.
Good luck.
/W

 

[Workingclasshero]

Worked in the tool industry 20 years ago and built tools up to 50 tons each.
When we needed to drill in hardened steel and other hard materials, we used regular concrete drill bits intended for hammer drills that were sharpened (much cheaper per piece compared to special drill bits).
Then they were set up in large drilling machines that ran at the highest speed with manual slow feed and constant cooling.
It was like cutting through butter.
The risk when drilling is that the material gets too hot and hardens the steel, so constant cooling is essential.

I have also successfully done this, even drilled with tile bits in steel.
The problem is that it can get so hot that the brazing of the carbide plate melts and the cutter comes loose, so use cooling.
No, rarely does the material harden...
It did happen to me when I was drilling in train tracks that are self-hardening, a strange alloy...
/W

 

[Workingclasshero]

I strike first with an awl so the drill doesn't slip around, then I recommend a step drill.

[link]

Unless it’s stainless steel as some stainless materials become work-hardened. Center punch very carefully or not at all.
/W

 

[J-banan]

If it's not stainless as some stainless materials become work-hardened.
Center punch very carefully or not at all.
/W

The one I linked worked great. Drilled 40 stainless pipes without any problem.

 

[Totte_S]

Hi
One should not press hard, never!
Start with a smaller drill bit and continue with larger ones.
Suitable steps could be 4mm, 8mm, 12mm.
Use oil or cutting fluid.
The larger the drill bit, the lower the speed.
Ensure that your drill bits have sharp edges.
Good luck.
/W

How do you mean that you get holes in stainless steel without pressing hard? Everything is of course relative, but you won't even get a new quality drill bit to start cutting if it's stainless steel. You must have drilled more than me, but I've still made a few hundred holes in stainless steel.

 

[Workingclasshero]

How do you mean you get holes in stainless steel without pressing hard? Everything is of course relative, but you won't even get a new quality drill to start cutting if it's in stainless steel. You've probably drilled more than me, but I've made a few hundred holes in stainless steel nonetheless.

Right drill size, right pre-drilling, right drill sharpening, right lubricant.
Then as you say, "everything is relative." What I think is just right, you might think is really hard.
When I drill in truck frames with a 14mm drill bit, I have a special attachment for a pneumatic drill machine, in the attachment I place a chain as a counterhold, and then the attachment has a long lever I press with, so there I press very hard... or rather with the right pressure for maximum removal, which is then linked to, among other things, the sharpening of the drill bit.
But then I have pre-drilled, right drill, right speed, and right lubrication.
Once I drilled with a 100mm hole saw where I only had half a hole to drill, ran without a center drill and with guidance around the outside of the drill bit.
It worked well with the given conditions above.
/W

 

[Totte_S]

Right drill size, correct pre-drilling, proper drill sharpening, right lubricant.
As you say, "everything is relative." What I think is just right you might think is extremely hard.
When I'm drilling in truck frames with a 14mm drill, I have a special attachment to a pneumatic drill machine, in the attachment I set a chain as a counterhold and then the attachment has a long lever I press with, so there I press very hard...or rather with the right pressure for maximum material removal which is then linked to, among other things, the relief of the drill point.
But I have pre-drilled, right drill, right speed, and right lubricant.
I once drilled with a 100mm hole saw where I only had half a hole to drill, ran without a center drill and with guidance around the outside of the drill.
It went well under the above-given conditions.
/W

Drilling with a lever arm can probably be considered as pressing hard…😉

 

[Argastesnickaren]

I've done that successfully as well, even drilled with tile drill bits into steel. The problem is it can get so hot that the soldering of the carbide plate melts and the cutting edge comes off, so use cooling. No, the material rarely hardens... It did happen to me when I was drilling into train tracks that are self-hardening, a strange alloy... /W

Exactly, many stationary drills have a pump for cooling. The largest drill machine we had was a German one from World War II with a 3 m boom so you stood on the parts we were drilling into. Cast iron was no problem to drill with a 100 mm drill, like butter.

 

[Workingclasshero]

Drilling with leverage can indeed be considered as pressing hard…😉

But not really......
Yes, you do, but above all, you don't wobble around as you easily do with freehand, which can lead to damage to the cutting edge.
You get a steady direction and steady feed, which is harder with freehand drilling.
For freehand drilling from about 8mm and upwards, I prefer drilling with less release, it bites less, less pressure is needed, rounder holes, and fewer burrs on the exit hole, just advantages.
/W

 

[Daniel Riccius]

Putting my entire body weight (90+ kg). Tried both with a screwdriver (max 1500 rpm) and a hammer drill in drill mode.

Could it be another metal than stainless steel? Does it matter?

Hi,

Solved the problem with these drills:

https://www.hornbach.se/p/borrset-alpen-profi-multicut-universalborr-3-delars/8712534/

which have tips made of tungsten carbide.

Daniel