Small square holes

[Ray Dunakin]

Can someone recommend a tool or method for making small square holes? Anywhere from 1/8" on down.

[marc_reusser]

How deep do you need to go, and what material? What are you trying to make/do?

FWIW, If there are not too many you could mill them out with a .010-.030 mill bit (available through McMaster-Carr)...then chisel the remaining radius corner square. (Mission-Models makes a 1mm and 2mm chisel that could work in deeper material, otherwise just use an Xacto in thinner stuff.)  You could also make a "punch" out of 1/8" square brass stock, thin/sharpen the end from the inside (so that the outside edges remain straight/true/square)....the just whack away. (I believe they make hardened steel tools like this,,,but have no idea where/who).


MR

[DaKra]

Drill a hole and square it off with a jeweler's tapered, square profile file.    Very easy to do one, but hard to precise consistent results on multiples.  It might help to add a tape stop to the file at the maximum size of your hole.    Then there's the traditional, old-fashioned laser cutting.   

Dave

[JohnP]

You could make a punch out of an old drill bit. The small size means a Dremel green grinder should do it. You can also buy broaches down to 1/8" square if you need to go through thicker material. McMaster has them.

John

[finescalerr]

Drill it with a square drill. -- ssuR

[SandiaPaul]

Square drill would work, yes.

http://www.youtube.com/watch?v=9qEhyQfbImY

paul

[Ray Dunakin]

Square drill would work, yes.

http://www.youtube.com/watch?v=9qEhyQfbImY

Wow, that's freaky!

[marklayton]

Ray -

Lee Valley Tools makes square hole punches, but the smallest is 3/16"
http://www.leevalley.com/US/gifts/page.aspx?p=65380&cat=4,54&ap=1

Eurotool makes some small square hole punching pliers.  Here is the 1.5 mm model:
http://www.amazon.com/Eurotool-EuroPunch-1-5mm-Square-Pliers/dp/B003JIMQIY

If the stock is paper or thin card stock, scrapbooking stores sell cheap punches in many sizes.

Mark

[Malachi Constant]

Well Ray, you still haven't said what material you're cutting ...

You can get square brass tube ... file the rim nice and sharp and make your own little punches for thin styrene, paper etc ...

Cheers,
Dallas

[Ray Dunakin]

Most recently I was cutting 1/16" square holes in styrene. I'd drill a small round hole and then carve out corners with an x-acto. Kind of tedious, and hard to do very accurately. But I can foresee the need to do something similar in brass on some future project, too.

[marklayton]

Ray -

I've never seen a square hollow punch that small.  You could use brass square tube as Dallas suggested, but it will dull fairly quickly.  Wouldn't be too hard to start with some good steel round tubing, and forge it down over a square mandrel.  With stock this small, a propane torch will provide plenty of heat.  Then carefully file or mill the outside square, and file a bevel on the inside with a needle file.  A good starting point might be McMaster-Carr's 3/16" OD 4130 alloy steel tube (p/n 89955K11, $19 for a 6-inch piece) with an 0.035" wall thickness.  Bring it back to a nice red heat and keep it red for a few minutes, quench in oil, and temper in the oven at 400 degrees for a Rockwell hardness of about 47.

Mark