How do I drill through hard metal?

[kniv]

Always when larger holes are to be drilled in metal, it is good to step up with 1-2 smaller dimensions first.

 

[Harald Blåtumme]

Drilled some drainage holes in an old large cast iron pot with about 15 mm thickness at the bottom, using approximately 10-12 mm Hilti TE-CX hammer drill to break through for the center hole, and then ran a 25 mm bi-metal hole saw from Biltema on the low gear (Hilti TE2-M). Worked fine, the hammer drill obviously made a hell of a noise but it's designed to drill in reinforced concrete so no issues. Used water cooling only, no cutting oil. Both the hammer drill and the hole saw survived the operation without problems.

Regular HSS metal drills had nothing to offer in this task, didn't make a dent, hence the aggressive solution with the hammer drill in hammer mode.

 

[drami]

Drilled some drainage holes in an old large cast iron pot with about 15 mm thickness at the bottom, used approximately 10-12 mm Hilti TE-CX hammer drill to break through for the center hole and then used a 25 mm bi-metal hole saw from Biltema on the low gear (Hilti TE2-M). Worked fine, the hammer drill was obviously very loud but is designed for drilling in reinforced concrete so no problems. Used only water cooling, no cutting oil. Both the hammer drill and the hole saw survived the operation without problems.

Regular HSS metal drills had nothing to offer in this task, didn't bite at all, hence the aggressive solution with a hammer drill in hammer drill mode.

Thanks, that was encouraging!😀👌🏻

 

[bryggstun]

Could it be stainless steel? It's usually more difficult to drill.

 

[drami]

No, it is not stainless.

 

[cpalm]

ordinary concrete drill bits intended for hammer drills that are sharpened (much cheaper per piece compared to special drill bits)

To elaborate on this, ready-made drill bits with "sharp" carbide tips are sold as "multi construction" drill bits.
And since TS misunderstood, you do not drill with percussion with these drill bits.

 

[Utsättaren]

Stuart, who has the channel Proper DIY on YouTube, I think has a good instructional video.

 

[Totte_S]

Damn good movie, I believe someone said almost exactly that in post #2 😁

 

[Utsättaren]

Yes, that's correct. But sometimes it's easier to see it performed visually.

 

[P-plats]

If you drill too aggressively, you can harden the surface, making it harder to penetrate. Use a drill of very good quality, such as Dorner or Gühring, and a cutting paste might be preferable to oil if you need to go through multiple layers, as it's easier to get the paste to the tip of the drill.

 

[Prodigys]

I agree with those who say buy cutting oil. Don't use regular oil. Makes a big difference.

[link]

Seems odd to use a hammer drill.

Why? A hammer drill is just a regular drill with a small hammering mechanism, so if you turn off the hammering, it makes no difference.

 

[Dan_Johansson]

Above all, impact drills rarely have gears, meaning the reduction of the speed has to be done by the motor, via the trigger... Difficult to maintain a consistent low speed...

Better to use a regular screwdriver with two gears...

The question is also how good it is to drill holes in load-bearing beams?

 

[Prodigys]

Above all, hammer drills rarely have gears, meaning the reduction of speed has to be done by the motor via the trigger... Difficult to maintain a consistent low speed...

Better to use a regular screwdriver with two gears....

The question is also how good it is to drill holes in load-bearing beams?

I would argue that this is not true as the vast majority of hammer drills are almost identical to their corresponding screwdrivers and therefore have the exact same functions in addition to the hammer mode.

 

[Harald Blåtumme]

Stuart, who has the channel Proper DIY on YouTube, I think has a good instructional video.

[media]

Yes, I know exactly how to do it. It's just that sometimes you have to resort to brute force as a substitute for the ideal cutting maneuver at low speed with high-quality HSS metal drills and strong pressure. I didn't have access to the latter, so I used a hammer drill and a hammer bit intended for reinforced concrete. This makes iron powder instead of iron shavings in the drill hole—maybe not "right," but the hole gets done. The drill head with tungsten carbide cutters doesn't care if it's concrete, rebar, or a steel beam/cast iron pot that needs to be drilled through, as long as the cooling works.

 

[Dan_Johansson]

I would like to argue that this is not true as most hammer drills are almost identical to their corresponding screwdrivers and therefore have the exact same functions apart from the hammer mode.

Since Ts mentioned 800 watts, I assumed we were talking about a corded machine here... 🤷‍♂️