View Full Version : Square tubing bender question?

10-04-2005, 07:31 AM
Hey guys!
I must be getting old! I'm drawing a blank on this one.
I need to build a couple of luggage type racks for a quad (ATV).
I want to use 1/2" square tubing and have radiused corner bends.
I machined the main die and was going to build a simple bender that I saw some years ago.
One problem...I can't remember what the bender looked like.
I could build it like my big mandrel bender but this one was much simpler.
Has anyone got any pics or links for one of these?
Another thing...I made this die to hold only half of the tube depth. The other half would be supported by the follower die.
Is this the best way or should the main die support the whole depth of tubing itself?
I read a thing on Google last night and they said square tube really gets wedged into the die.
I've bent a ton of round tubing and pipe but never square stock. Thanks!

George Barnes
10-04-2005, 09:02 AM
I don't have any pics of a simple bender, but I do have a 1" square tube die set for a Hossfeld. It is kind of hard to see in the pic but the edge of the form die does not have a flat surface. It is V shaped with an included angle of about 18 degrees. This collapses the inside wall of the tube and helps with getting the tube extracted from the follower bar. The are still a bear to get out of the follower anyway. The entire thickness of the tube is contained in the follower. I know that the V shape is important as I tried making one in a different radius and just a flat edge and it wouldn't work.


Hope this helps.

Mike Burdick
10-04-2005, 11:10 AM

For what it's worth...

For a simple three-point square tube bender here is what I made and use (see photos). This works off a simple hand operated bottle jack. The “die” for one-inch thick wall tube, is just a 5-inch round piece of bar stock with a 3/8-inch diameter, 3-inch long piece of round bar to the middle of it (parallel to the tube). The ends of the 3/8-inch piece can be cut flat, as they will automatically form a nice tapered dimple when used in the press. I also machined a small flat on the opposite side so that it made it easier to hold on top of the jack. Sides aren't needed on the die! For 1/2-inch tubing, you can size the die accordingly and will need the pins much closer together on the bender. (Try a 3/16-inch diameter rod for the "dimple" maker.)

Anyway, to bend the tube, just put the die such that the piece of 3/8-inch steel will push in the inside of the tube and collapse it - then once it hits the round bar it will bend nicely. The tube sides will bulge a bit, but they will be uniform if the tube is put in the bender square. Oh...for the pins on the top of the bender, one just needs a one-inch grade 5 bolt to bend against. A minimum of a 1-ton bottle jack is needed. You can drill more holes across the top of the bender for different bends and pressures.

The bender shown in the photo (I also use it to bend 2-inch rigid pipe) is 1/4-inch plate on the top, 8-inch X 24-inch, 1/2-inch X 2-inch X 12-inch flat bar, and the bottom, 1-inch plate. It is typical run-of-the-mill A36 steel. The use of "John Deere" green paint is a must! http://bbs.homeshopmachinist.net//wink.gif

The bend shown in the bottom photo is made on a 1-inch thick wall tube with a 2.5-inch radius. For your 1/2-inch tube, you can get that radius down to at least 1-3/4 inch - perhaps less!



[This message has been edited by Mike Burdick (edited 10-04-2005).]

3 Phase Lightbulb
10-04-2005, 11:22 AM
1/2" Square tubing? Come'on!! You can bend that with your knee http://bbs.homeshopmachinist.net//wink.gif

10-04-2005, 11:45 AM
Thanks, but I can't visualize it. A 5"x1" disk? Anything like the Hossfeld in the photo above?

10-04-2005, 12:26 PM
In a post last year about bending square tubing, I posted some photos of the bending die that I built for 3/4 sq. tubing. I works great! http://bbs.homeshopmachinist.net//Forum1/HTML/010584.html

Mike Burdick
10-04-2005, 12:29 PM

Nothing so fancy! Sorry, I don't have time to get a picture but here's a sketch. In my case, I used a piece of solid bar stock (5-inch in diameter and 4-inches in length. My bender is 4 1/2-inches in width.) and tacked the 3/8-inch diameter rod on the top. This is used to start the “collapse” of the tube wall on the inside of the bend and make a nice “dimple” in it. To make the bend look nice, make sure the piece of rod is centered in the bend. The flat on the bottom is handy to keep the “die” on the top of the bottle jack and will “automatically” center the rod in the bend. It would be handy to drill a shallow hole to stick the end of the jack in as well! One thing to note: the smaller the diameter of the dimple rod the less bulge in the sides of the tube but it also needs to be large enough to still get the inside wall of the tube to bend in properly. You’ll have to experiment to determine what you want. For the dimple rod, just cut it from an old bolt minus the head and threads. When you do make bends with it you’ll find that they will be uniform and very professional looking.


Gosh, that's a poor looking sketch... http://bbs.homeshopmachinist.net//frown.gif

Okay...Just looked at Mel's link above! Mel has the same idea only his is "Fancy".

Mel... very nice job!



[This message has been edited by Mike Burdick (edited 10-04-2005).]

10-04-2005, 02:07 PM
Thanks guys!
I always wondered how you'd get the middle to collapse. Ha...I though it did it on its own.
That little 1/2" by 1/16" wall square tubing it harder to bend than you'd think.
I have actually bent some of it in my ring roller. Unfortunately the rolls are far too big for this and it bulges out the sides too much.
Mike you where right on the money. The die I made is 1 3/4" diameter.
The bender I'm thinking of just had a simple handle for the bending power. It was for small tubing also.
Guess I'll have to add the creasing rod to my die. Thanks again!

10-04-2005, 02:34 PM
Mike, how much crush do you get on the 2" rigid pipe with the home made unit?

I assume we are speaking of a 2" ID (2-3/8" OD).

Mike Burdick
10-04-2005, 03:26 PM

Yes we’re talking about the same pipe. In the photo above you can see one of the dies on the pins (flat) that I use on the 2-inch pipe. I make them from 1/4-inch plate and segment them together cutting each with the band saw. When it is put together, I take an angle grinder and grind the inside round – it doesn’t have to be perfect, although it will come out very good since only the edges need to be ground down. This way I can use up all my scrap. For the bending shoe, I do it the same way, but remember it only has to be a quarter of a circle for 90-degree bends. Grease the end shoes well as they need to slide. I don’t think this will bend thin walled tubing (exhaust pipe) as this bending method will just kink it.

As for bending quality: My bends have approximately an 18-inch radius and have a little flattening. I also have to do it in multiple “shots” (typically three and it won't be noticed in the finished bend) to keep flattening to a minimum. I use old pipe that I bought from an oil company that used them to lay surface natural gas lines. This pipe is pretty good. On the “new” pipe, I have trouble bending it, as it’s not the same quality. I put the seam so it’s on the inside of the bend, which helps some. This bender was made so I could make “nice gates” and “fences” for my cattle corrals and pastures. Harbor freight sells something similar but when I needed mine, Harbor Freight didn’t exist (circa 1974)! I also don’t know how strong HF’s are – I use a 20 ton bottle jack and sometime it takes all of it.


Here’s a couple pictures of the segmented shoe:


[This message has been edited by Mike Burdick (edited 10-04-2005).]

10-04-2005, 06:28 PM
Mike...You shaped THAT with a grinder? Nice job!
Actually it's pretty good idea to have smooth fences etc. around livestock anyway. Sure cuts down on the vet bills especially with horses.
Ooops...you already knew that!

Mike Burdick
10-04-2005, 07:03 PM

It wasn’t hard at all to finish with the angle grinder. Each segment (1/4-plate) is cut with a band saw such that the low edge will match the pipe exactly at that position. All one has to do is grind to that point when everything is bolted together. It’s actually pretty easy and is much easier than using a lathe with 40 lbs spinning on a radius of 18-inches. Besides, I don’t have a lathe that big! http://bbs.homeshopmachinist.net//frown.gif

Russ, how about posting a picture of the hand bender you made? Seems on small tubing, your idea would be the best way to go!



[This message has been edited by Mike Burdick (edited 10-04-2005).]

10-05-2005, 12:03 AM
Mike, I must have led you astray! I've only got the one die made so far. The bender I'm thinking of, I saw here a number of years ago. My old teamroping partner (he's moved back east somewhere or I'd ask him)started a trailer mfg and was selling high clearance flat deck trailers to the local guide/outfitters. They where a multi purpose trailer that had walls but no roof. He set up this simple bender to make dozens of removeable hoops for a canvas roof for the transport of pack horses to the mountains.
The thing would bend 3/4" square tubing like nothing and was very simple.
It had an open face and split open somehow when you returned the handle to the start.
That's the part I can't remember...how they rigged up the linkage.
I guess I'll have to stay at a Holiday Inn for a night and I'll get it figured out!
I'll post pics if I ever get this done!

10-05-2005, 03:08 PM
by the time you find a chunk of iron, cut it, drill it, try it out you can purchase a model3 shoe. $175-225 each..

I posted the model3 hole pattern on www.metalillness.com (http://www.metalillness.com) site in a gcode file.