Drilling Holes In 3mm Galvanized Steel Straightforward?

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Bill Shields
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by Bill Shields »

arborist wrote: Tue Nov 29, 2022 4:13 pm
Bill Shields wrote: Tue Nov 29, 2022 11:17 amFor 3mm (.125") I would use a hole saw based on the size recommended
He says in the original post that he wants from 8mm to 20mm diameter. The smallest hole saw that Starrett make is 14mm (9/16th of a freedom unit).

---

To the OP: you are in a good position having a drill press as the driving force behind whatever cutting tool you choose. Slower will always be better. That same advice extends to your own arm on the handle.

In anything above 1/2" (13mm), a hole saw is likely to be cheaper than a twist drill. Starrett are good; Bosch also good but use a non-standard arbor; Abracs (Toolstation) or Erbauer (Screwfix) will do the job.
I was referring to 3mm thick.....
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pollys1dad
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by pollys1dad »

jcfx wrote: Tue Nov 29, 2022 4:58 pm Aside from the step drill NP317 mentions there are also rotabroaches, basically smaller versions of
annular cutters. Step drills and rotabroaches have been my go to for making small holes in thin materials.

https://www.blairequipment.com/rotabroach-cutters
I've had a quick Google of Rotabroach cutters, seem to be alternatives here in the UK. But don't know if they and Rotabroach are only suited to magnetic drills?
Everyone else, thanks for the input.
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by Bill Shields »

It is just an expensive hole saw not for use in hand held drivers.

Depends on your hole tolerance when comparing to other hole making methods.
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NP317
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by NP317 »

Bill Shields wrote: Tue Nov 29, 2022 7:01 pm It is just an expensive hole saw not for use in hand held drivers.
Depends on your hole tolerance when comparing to other hole making methods.
From the above Rotabroach webpage:
"Arbors fit 3/8" and 1/2" hand held drill chucks and use either spring loaded pilots or skip-proof pilots which eliminate pre-drilling operations."
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by Bill Shields »

I know what their www page says....but in reality they are very tough to use hand held and I would not recommend it on 3mm material.

I have a couple of scrapped units from a similar company Hougen -> once you get into the material, any tilt and it's bye bye birdie.

Not to say that I have not destroyed a small dumpster full of hole saws over the years...but since they are practically a consumable...I do not get emotional when they lose a few teeth.. :mrgreen:

But then the original request states a pillar drill, so it is a moot point.

The one thing none of us has thought to ask

How many holes?
What positional accuracy?
What diametrical accuracy?

Ok ...three things...
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by pollys1dad »

The one thing none of us has thought to ask
How many holes?
What positional accuracy?
What diametrical accuracy?

Something like this.
Thanks.
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rmac
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by rmac »

That looks like a chassis for some old vacuum-tube based electronics. I seem to remember that folks used to make those holes using knockout punches. The name "Greenlee" comes to mind. Maybe that's what you should be looking at. I don't remember those old chassis being 1/8" thick, but maybe they were. I looked up Greelee punches and it says they're good for up to 10 gauge mild steel, which is 9/64" (3.5 mm) thick.

-- Russell Mac
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by Bill Shields »

Agree on punches...have a box of them...even one that is square.

however another question ..

Holes before or after folding?

If it were me I would lay it out and find someone with a turret punch
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by pollys1dad »

I intend to lay it out flat then hole it, the pillar drill has a large enough throat.
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by pollys1dad »

I have a couple of suitable UK version of the hole punches, but only available 16-50mm.
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by Bill Shields »

assume then that you are making only a prototype to test concept?

or doing production?
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Re: Drilling Holes In 3mm Galvanized Steel Straightforward?

Post by pollys1dad »

Prototype with view, to small scale production, small one man business. Not thinking of CNC plasma cutting etc :)
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