Square holes ?

[Herbiev]

I need to make a 1/8" square hole in a piece of 3/16" steel plate. Anyone got any ideas on the best way to go about this ?
Tia Herbie

 

[GailInNM]

Herbie,
One way is to make a square hole in round stock and press/Loctite that into a round hole in your plate. Photo is of a chuck key I made for a magnetic chuck with a square operating shaft.

I milled a slot the length of the round stock. The slot was deeper than the square needed. Then milled off the top to make the slot the right depth. Silver soldered another piece to form the square and then turned the whole mess round.

Of course a square broach is another option but the makers of them think quite highly of them and charge accordingly.
Gail in NM

 

[Herbiev]

Thanks for that Gail. I too thought of a broach until I saw the prices.

 

[BaronJ]

Hi Herbie,

Drill an 1/8" hole and use a square needle file to get the flat edges. You could make a slotting tool to do that job as well. 1/8" inch square tool steel is commonly available. Put a short length into the end of a piece of round bar and use a pedestal drill as a press. Though I must admit that I would use a file.

 

[Herbiev]

Thanks Baron. I have an arbor press so I may try the 1/8 tool steel on a piece of scrap first.

 

[lohring]

The problem with pressing a square tool through a hole is accuracy. I've made several shaft adapters this way and the square isn't concentric with the hole. As long as this isn't a problem, the method works great, at least up to the 3/16" squares I've done. The best method for a lot of holes is the rotary broach.

Lohring Miller

 

[SmithDoor]

A small file for a few holes. I have also use a punch grinded to the shape need and red hot plate fast and low cost

Dave

I need to make a 1/8" square hole in a piece of 3/16" steel plate. Anyone got any ideas on the best way to go about this ?
Tia Herbie

 

[Herbiev]

Regarding the punch method, I was thinking of 1/8" square tool steel ground to a round point and pressed into red hot plate to ensure concentricity

 

[GLCarlson]

I need to make a 1/8" square hole in a piece of 3/16" steel plate. Anyone got any ideas on the best way to go about this ?
Tia Herbie

Sure. Get a drill that makes square holes- you'll need to touch up the corners a little.

Yes, these really exist. And are commercially available. It's an oddball more-or-less triangle shaped bit that drills a rounded corner square hole.

Everybody needs a few of these...if only to blow the mind of the typical non-HSM guys. Always good for a few pints at the local...

 

[dman]

Sure. Get a drill that makes square holes- you'll need to touch up the corners a little.

Yes, these really exist. And are commercially available. It's an oddball more-or-less triangle shaped bit that drills a rounded corner square hole.

Everybody needs a few of these...if only to blow the mind of the typical non-HSM guys. Always good for a few pints at the local...

Yup, just an application of solids of constant width..

Shapes and Solids of Constant Width - Numberphile: http://youtu.be/cUCSSJwO3GU


How to Drill a Square Hole: http://youtu.be/L5AzbDJ7KYI

 

[Swifty]

I usually end up drilling triangular holes in sheet metal without really trying, drill just seems to bounce around.

Paul.

 

[Krutch]

If you only need a square hole but hot all the way through the plate, It can be made using a woodruff cutter. Plunge from one side half way through flip plate and plunge from other side at 90 degrees to first cut meet and adjust to allow square size. May need to calculate and approach by trial & error. This works for carriage bolts & such.
Some square ID bushings can be bought and round hole to fit drilled. May weld/braze or some other fastening made to keep in place.
I think Essentra (formally Reid tool) has them, Or you could make your own by milling half your square in a length of rod and cut in half & mate to form a square of suitable length.