making 1/2X1/2 inch square holes in 1/4 inch stock

Take it to a shop with a Piranha or Ironworker hydraulic machine. Pick it up in four hours. There is no modern inexpensive tool to do it I know of. If you find one, please inform me, as I would like to do some similar. But mine has to do with rod, and a drill press does that fine. I just can't find any square bits around these parts.

Please let me know if you find any of those, too.

Steve

There are a number of sort-of affordable tools that could do this. Let's see .. surface area of the hole is 4*1/2*1/4 = 1/2 in^2. Assuming 35 ksi steel, that would take about 17,500 pounds of pressure or a tad under 9 tons. You could cobble up a fixture on a 20 ton shop press that could punch those holes. It will definitely need a stripper mechanism of some sort. Or, you could go find a Whitney No. 20 10-ton manual punch and buy an appropriate punch and die.

You need to know the actual shear strength of your 1/4" steel bar. When you buy it from a reputable steel vendor, you can request the actual lot test information, and that will tell you.

You can also still buy nice 1/2" square blacksmith punches, and forges, and hammers.

Or, you could pay someone to EDM you a really nice plasma cutting template and use a plasma cutter.

But certainly the best way is to use an ironworker with appropriate punch/die. That's what they do. Punch, shear, notch.

GWE

It could be done pretty readily on one of the many 5x10 CNC plasma cutters out there.

Rent a plasma cutter for a day for $50 and hand cut them. You can make a cutting jig from plywood.

Oh yeah, there is also the old square hole drill trick. Still used in some parts of the world, and many old blacksmith's shops.

Google for "Watts Brothers Tool Works"

Square hole bits? Heck---just make some.

Drill a hole the size of the diagonal (SQRT(2) x 1/2 = 11/16) & fill in with welds. The weld area is pretty small: a triangle, or or less, with a 1/2" base & 3/32 height.

Bob

Thanks for reminding me that the holes could be made with a plasma cutter. Several years ago I came to the group for advice on a plasma cutter and Ernie swayed me rightly to the Hypertherm Powermax 600. I did get one and I use it for bigger cuts. I did not think that it would work for these small holes and be fairly exacting. But I certainly will try the method Bernie suggested first and if my skill is not good enough I will go down the line and will try the other methods suggested.

Thanks for your reponses. As always you came through with great ideas.

Best Regards,

Ray R

If you make a piece of copper tiny bit bigger than your steel square stock you want to use that might make filling in easier but it might be hard to remove the copper as well.

Fran

take your cutting torch or perhaps your plasma torch find a nut which fits over the nozzle and bottoms out with say a quarter or three eights of nozzle sticking out. now make a square template you can run around inside of with the nut resting on top of the template and the nozzle following the side of the template. such template could be a washer modified with a square file. Devise some way of securing the washer above the work, one of those magnetic blocks with the button on the side is probably the best but clamping it on top of another nut will work perhaps an extension to the washer will be needed. I make square holes for carriage bolts on occasion though I usually do it free hand but have a bunch of templates to attach to my magnetic block for round ones. If you have a lathe you can turn down the end of the nozzle so it isn't tapered and the nut won't be needed or propane tips often aren't tapered. Once you get a hole pierced it helps to turn down the heat I find.

Fran

As the kids would say, "SHUT UP!" I learn something every day.

Steve

Make a template, and when you make your pierce hole in the metal, do it in the center of the intended hole, then go to the outside lines. Also concentrate on having the torch perpendicular. Do a couple of holes and then adjust just in case they're a little off. You don't want to be dressing a whole bunch of slightly off holes. (why does that last sentence look odd?) But you get my drift.

Right?

Steve

Square broach...

Actually, since these holes will be welded up, just whack 'em in freehand, cutting to a soapstone line. Chip chip to take off the slag on the back, move to the next hole. Don't use the holes to align the posts, just clamp them in place and weld all up.

After you cut two or three holes you'll be real good at it. Start in the middle somewhere, not right at the end where people will see it more.

Grant

wAY COOL!

(Ive seen these in use on Swiss screw machines btw, along with attachments that make multi sided square, trianglular etc etc "turnings" on the same lathes.

Gunner

"Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

It is called a square broach, it is a common product. You drill a slightly over 1/2" hole and then broach it. I have a set of broaches that go from 1/2" round to 1/2" square in several steps (several broaches to be used successively) You need a appx 3 ton press to use them.

I have a 600 and cut 1/2" AR400 with the use of Fine cut - but with the saddle nozzle. It is beyond the scope of that size but I've cut some beautify edges. Wish I had the 1000 and someday at least that level upgrade. The T60 upgrade torch is well worth it - with fine cut it rocks much better.

Mart> Thanks for reminding me that the holes could be made with a plasma cutter.

The template should be 1" or more in height - be sure it touches and makes a planar connection to the wood with the insulator sleeve. The torch has an offset of 1/2" - as the barrel is 1" and the cutting center is 1/2 of that. Kerf is needed to be measured on scrap or in the hole - but the kerf might be used as oversize the hole or modify the block...

Test, try - test. You can test on thin material - try 3/8 or 1/4 getting the general kerf and block size. The burning through might raise a bump and what you do is stop the torch - grind flat and then you can continue to the edge or around the block.

Mart>> Thanks for reminding me that the holes could be made with a plasma cutter.

I hear that the Max45 has a new torch design that is even better, as long as you can live with 45A capacity.