2x2 tube rolling destroying tube

Okay so here's the story, I have some 2x2 14 gauge tubing that I need rolled into a 4-ft inside diameter and I have had a real hard time finding somebody to do it. I finally found a guy and we put it in his large powered rolls and it is completely ripping the tubing apart. I don't think these guys do a lot of rolling, and the guy that was doing it I think has almost zero experience, and I'm trying to figure out if it's their machine, the guy, or this is too tight of a radius.

I asked the guy exactly what was going on because I saw these giant dents in the side of the tubing and also one side of the tubing completely ripping apart.

You can see from the pictures that on the one side that I'm taking pictures of only one Edge is ripping apart, and the guy was saying something about his boss was saying to loosen the top guy as they go. I kept telling the guy that it looks like the top roller needs to be tightened, because the wall on that side was getting squeezed in on only one Edge which was the edge that the top die was on. He kept saying no that wasn't the problem but it was only happening on one Edge on one side.

It is to be noted that the shop said it was ready, then when I got there I had to wait an hour for the guy they delegated it to to drive back from home and start doing it because he forgot. The guy was neither pleasant nor a gentleman and made it clear he was not happy to be there or basically exist at all.

1st Pic shows how one edge of one side is ripping apart, while the other edge was fine. The opposite side was perfectly fine
2nd Pic is general setup
3rd Pic show dents in damaged side. I couldn't really figure out how this even happened
4th Pic show detailed edge with roller setup

....to me I think its obvious that by loosening the top roller(on the nut of the roller that allows for lateral adjustment) was allowing the top to spread out while the bottom die held the lower 80 percent in shape, thus causing tearing at the top edge. AM I WRONG???...Because these guys had all other kinds of explanations and would not listen to my reasoning. Then also wanted 50 bucks

The next piece of tubing I roll will be my first, so this may be completely worthless, but a 4ft diameter circle feels very small for 2" tubing. Even a 4ft radius would feel small

Did they try to get there all at once or gradually?

As stated that's a really big ask

That's a lot of stretching and shrinking going on there. I agree with Fred w above.

With today’s AI driven sources of information, coming to the GJ will get you a different approach to solving your problem.

Hello, Tbirkey, as a former engineer, when I would be attempting a process I was unfamiliar with, especially involving materials, I would start at the beginning. The first place is to accurately identify the material I wanted to bend. Now remember, I was an engineer way back when dinosaurs roamed the earth and we had no internet. We hadn’t invented that just yet for everyone, so we used text books provided by the men and women who produced such items. In fact, I myself produced technical articles, manuals and user guides to all the stuff I invented. But I digress…

If I was in your shoes I’d go back to the source where you bought your square? Tubing and inquire about its properties. It’s possible that what you have is next to impossible to bend unless you apply a special process to it.

Identifying the proper process. Now that you know if your material can be bent, I would need to know “what to call the process”. Doing a quick Google search I found out “bending” is not the proper term. Bending shows smaller diameter radiuses bent into a straight section, not a continuous radius over the whole length. Bending tells the internet bend a pipe, like bending an exhaust pipe, so my search provided no companies providing expertise in forming a radius over a whole length. It was only after a bit of word changing did I come up with the term “structural shape rolling”. Once I had that correct term I could then search for that and find venders that had expertise and the correct equipment to form a radius in the whole length of a section of square tubing.

A good tip for GJ members that might seem trivial is to fill in our location. With that in our Avitar, members reading our thread out of an interest in the subject matter, might post a reply like, I’m in your town too and I would just go down to bendy mcbendersons and have them get your roll on. But, since I don’t know where you are located, I may not post a reply.

Let’s say you have some tubing that cannot be bent using the “roll forming” method. What to do then? If it’s weldable and you don’t need a uniformly smooth radius, a series of cuts could be performed along the length perhaps 3/4 of the distance through. Then, the tubing could be drawn together compressing the cut ends together. Once you have discovered the ratio of cuts to reaching the desired 4 ft. Inside diameter, then you weld all the cut lines closed.

I know you are now saying, Gahrajmahal, you are a crazy person. No one would do this. But we did do this. If we needed a “mandrel bent” or pipe bent with no diminishing inside diameter, this is (was) a way to achieve it.

Anyways, hope you post your solution to this. Here are some photos from my research into this problem.

mike93lx said:

The next piece of tubing I roll will be my first, so this may be completely worthless, but a 4ft diameter circle feels very small for 2" tubing. Even a 4ft radius would feel small

Did they try to get there all at once or gradually?

Click to expand...

I asked him if he went gradually and he said yes, but then again this guy did not want to be there and made it known he had to come back from home to do this job and wasn't happy about it

Fred w B 01 said:

As stated that's a really big ask

Click to expand...

The diameter? Ive seen this exact t
Radius and material done

tbirkey214 said:

The diameter? Ive seen this exact t
Radius and material done

Click to expand...

I'm not an expert, but shouldn't those dies be deeper?

Sounds like the guy didnt give a ****, I would try to find another shop

PCustoms said:

I'm not an expert, but shouldn't those dies be deeper?

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I would think yes, this was a very large machine, but these are the only guys they had for square tubing. I would imagine that if the flanges were deeper than the material than it would be physically impossible for the sides to blow out

You can curve that material to that diameter but you probably can’t do it with a roll bender. The majority of our work is in aluminum, and we have regularly run up against the limits of what can be roll bent and have to switch over to stretch forming. This eliminates the inside face curving in and keeps the edges clean. 14 gauge steel is pretty stout for that diameter.

Like previously stated, find a different company and if you put your location in your profile, it could be helpful.

I'm no expert, I have a swag offroad hulk roller but I've only ever rolled round tubing. Swag claims their roller can do 36-48" radius on square tubing (up to .125 wall) and I think they are a reputable company. The Eagle Rolling Bender manual, pg 4 claims min radius of 40" on 2x2x11ga. It's certainly a tall order but seems achievable.

I don't think the dies in that machine, pictured above, need taller flanges. The sides are scrubbing the material, not rolling which is probably contributing to the tubing getter scraped. The taller the flanges, the more scrubbing on the outside edges of the flange (if that makes sense?). If the side dies were independent and rolling on a vertical axis then I could see a benefit of them supporting the entire tube wall.

In your pictures, the side that's not getting all mucked up is supported by vertical rollers. I only mention that because you made a point to say that only 1 side was getting torn apart.


It's been a few years since I've rolled anything but I think I used some lube/grease on the tubing, that might help the sides of your tube.

You would have much better success going with a fabricator that uses bending tooling / equipment that uses internal mandrels (sometimes called a "mouse")... The "mouse" is used on the inside of the square tube and its purpose is to resist the inward collapsing of the tube walls when bending... I used Chicago Metal Rolled Products when I had a project that required 4" square 7 gauge mild steel...

A three roll machine has its limitations and cannot resist the normal inward collapse of the tube...

Example of a square tube mandrel

Snip's said:

You would have much better success going with a fabricator that uses bending tooling / equipment that uses internal mandrels (sometimes called a "mouse")... The "mouse" is used on the inside of the square tube and its purpose is to resist the inward collapsing of the tube walls when bending... I used Chicago Metal Rolled Products when I had a project that required 4" square 7 gauge mild steel...

A three roll machine has its limitations and cannot resist the normal inward collapse of the tube...

Example of a square tube mandrel

Click to expand...

I've never seen that on a rolled tube, interesting

My last place I did all the man and rolling gates out of 2x2x.120 tubing. We wanted the tops to roll up to a peak so I had a fab shop roll them for me. Problem was the tubing was too thin and would cave the side walls like your issue. My buddy who ran this shop stepped it up to 3/16” wall and that solved the issue.

I know I’ve rolled plenty of 1” and 1-1-4” in my shop and unless I go .120 wall I have the same issue. Why this is I don’t know

PCustoms said:

I've never seen that on a rolled tube, interesting

Click to expand...

Here is an example how an internal mandrel bender works, in this case for a round tube profile, but square is similar...
The mandrel is stationary and the tube is pulled over the mandrel...

internal mandrel bending

Snip's said:

Here is an example how an internal mandrel bender works, in this case for a round tube profile, but square is similar...
The mandrel is stationary and the tube is pulled over the mandrel...

internal mandrel bending

Click to expand...

Like I said, I've never seen that used on a rolled tube....

PCustoms said:

Like I said, I've never seen that used on a rolled tube....

Click to expand...

OK... Pulled vs. Rolled...
You'll never ever see it being used with rolled tubing...
Different method, different tooling...
Limitations to both...

Snip's said:

Different method, different tooling...

Click to expand...

Right. And this thread is about rolling...

Also never heard it called "pulled tube". You pull pork, not tubing

pack with sand or lead shot
cap off,drain sand when done

elvee said:

You can curve that material to that diameter but you probably can’t do it with a roll bender. The majority of our work is in aluminum, and we have regularly run up against the limits of what can be roll bent and have to switch over to stretch forming. This eliminates the inside face curving in and keeps the edges clean. 14 gauge steel is pretty stout for that diameter.

Click to expand...

I beleive my buddy did it with 14g to that diameter, but it might have been 1/8

b-dog said:

Like previously stated, find a different company and if you put your location in your profile, it could be helpful.

I'm no expert, I have a swag offroad hulk roller but I've only ever rolled round tubing. Swag claims their roller can do 36-48" radius on square tubing (up to .125 wall) and I think they are a reputable company. The Eagle Rolling Bender manual, pg 4 claims min radius of 40" on 2x2x11ga. It's certainly a tall order but seems achievable.

I don't think the dies in that machine, pictured above, need taller flanges. The sides are scrubbing the material, not rolling which is probably contributing to the tubing getter scraped. The taller the flanges, the more scrubbing on the outside edges of the flange (if that makes sense?). If the side dies were independent and rolling on a vertical axis then I could see a benefit of them supporting the entire tube wall.

In your pictures, the side that's not getting all mucked up is supported by vertical rollers. I only mention that because you made a point to say that only 1 side was getting torn apart.


It's been a few years since I've rolled anything but I think I used some lube/grease on the tubing, that might help the sides of your tube.

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Its wasn't touching the serticle supports you circled .

Also, I had a KAKA roller, and it refused to really roll square tubing at all. It could do 1" kind of but thatbw a s it. I even called the company and they basically couldn't answer why it didn't work, and I think they knew it didn't

Snip's said:

You would have much better success going with a fabricator that uses bending tooling / equipment that uses internal mandrels (sometimes called a "mouse")... The "mouse" is used on the inside of the square tube and its purpose is to resist the inward collapsing of the tube walls when bending... I used Chicago Metal Rolled Products when I had a project that required 4" square 7 gauge mild steel...

A three roll machine has its limitations and cannot resist the normal inward collapse of the tube...

Example of a square tube mandrel

Click to expand...

How much were they charging you for mandrel bending. I can hardly find anyone out here with a tube roller that doesn't want insane prices

Snip's said:

OK... Pulled vs. Rolled...
You'll never ever see it being used with rolled tubing...
Different method, different tooling...
Limitations to both...

Click to expand...

And I'm doing this to make stuff to sell... any pulling type machine is big bucks. Last place I called thaybdid that wanted 800 bucks lol. It has to be rolled on powered rolls because that's whatbthe average small shop has

PCustoms said:

Right. And this thread is about rolling...

Also never heard it called "pulled tube". You pull pork, not tubing

Click to expand...

Lol
I think he means form bending or whatever it's called.

tbirkey214 said:

Lol
I think he means form bending or whatever it's called.

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I think so to, but I've never seen a full circle done that way...

What you building?

PCustoms said:

I think so to, but I've never seen a full circle done that way...

What you building?

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Trellises

I used to build outdoorsy ornamental type stuff a couple years back with just a hand grinder in my backyard, and now I have the equivalent of a fabrication and machine shop in my garage and I'm trying to use it to make some extra money instead of just building things for myself. To be honest I spent all my money on tools and now I'm trying to use my tools to make some money LOL

To start with, 14 ga. is really light wall for that size and radius. I have rolled a lot of 2 3/8 16 ga. round and at 24 FOOT radius you get a lot of deformation so no surprise how much damage you are getting at 24 inches. You could do this with a mandrel bender, but you would be hit with a massive tooling charge for a 48" set of dies (one round, one straight) but it would still not close 360 degrees as you need a little straight piece to clamp to the round die (where the "pulling" happens). Only way with that kind of tooling is to do a pair of 180s and 2 welds. The rolling equipment you are using seems a bit light to me. I would suggest you find someone with heavier rolls and a lot more experience and work your way up in wall thickness until you can get an acceptable profile. Sadly you are going to have a lot of waste if you are using 20s but if you can roll 3 x 360 from 40s would be better.