Drilling Square Holes in Roll Formed Aluminum

There is in fact a device for drilling square holes in metal . Can't remember what it's called , but basically the bit is on a floating drive system that lets it orbit in a guide - square , triangular , or other shape guides are available IIRC . You will get corners raduised at the drill bit size ...

Seems I recall a triangular cutter of some kind for cutting square holes. Sorry, don't remember where or when or what it was called, but it was pretty cool.

"Rotary broaching".

Yep, It's called rotary broaching.

Rotary broaching requires the part to rotate as well as the bit.

If that won't work, try looking up 'watts drill'.

Watts bros. as of 2008:

Dave

Not anymore Dave.

Cool beans! hadn't seen that update.

Info on the Watts bits have been in the dropbox since '08...

Pricey either of those 2 ways.

Dave

How big is the desired square hole? How many holes? For small quantities of holes, 1/8" aluminum can be knockout punched if you need a hi-spec hole, or (my preferred way) nibbled if the specs aren't so tight.

As for mass production, I'd like to go visit the factory where they make Unistrut someday.

Tim.

A "Vika" brand is mentioned in although author says device shown is homemade. In following video, he uses it on drill press instead of lathe.

This has cropped up before and I saved this link to a bit of information about it

There is a tool for drilling square holes in metal.

You know how a normal 2-flute drill bit when used to drill improperly secured sheet metal will make something vaguely triangular? (The bit catches on one flute and pivots cutting a sort of straight line with the other until that bites and the first cuts another straight line, but not *very* straight, because the rest of the flute shape keeps it from being perfect by a long shot.

Well ... there is a special bit for the purpose, three flutes, in a holder which lets it wobble, and guides the bit properly. Three flutes makes a square hole, four flutes makes a pentagonal hole, five flutes makes a hex hole. I don't know whether they go to higher counts than that.

Here is an example set up for a lathe. A drill would need to have the guide on the bit holder.

Here is an animation on how it works.

And another:

Good Luck, DoN.

1. Can someone shoot me info on how to access the dropbox?

1. Cool beans! Dead nuts! ...All those sayings make me wonder where the heck they came from, but I'm well aware we have discussed them endlessly at times.

Regards, Joe Agro, Jr. (800) 871-5022 x113

V8013-R

Tim,

Hole is approximately 1/2" to 3/4" across (square).

Mass production. Thousands of holes per day are desired.

For that scale it sure sounds like a job for punching, unless there is a

At that level, just punch it. Most economically it'd be punched before, or as part of, the roll forming. The companies that do roll forming will look at the frequency of holes and the diameter of their dies and set it up on the line.

Tim.

To punch, the end user has to use an insert to support their "tube" and the tube is neither capable of receiving the insert (die?) or modifiable. Without the insert, the tube simply deforms under the press operation.

Did you specify the corner radius? If so, I missed it.

I assume that someone brought up the Slater rotary broach, right?

No. ...Because they have not done so yet. If they can find the tool that works, I sell the tool that drives their... Well... New tool.

If it's the wobble / shake / rock-n-roll broach thing, yes.