Sport Bar / Roll Cage Material

[Peanut Butter]

Awhile back HH was extending his Sport bar to the front of his jeep. Once we got the pictures, I thought he did a great job! But, this is an area that I really don't know much about. By that I mean the metal used. Some call it pipe, some call it tubing, and some like me don't know what to call it. So let me throw out some example and the metal guys can maybe smarten me up a little bit.

Chain Link Fence poles - tube or pipe?

Oil Filed Drill Stem - tube or pipe?

What thickness is a good compromise? Does thicker wall pipe have greater strength than thinner wall tubing?

Lately I've been building a pole barn out of 2 3/8 OD - 2 in ID oil field drill stem. Lots of it down here, makes a great pole barn structure. So here is a picture of it. Is it tube or pipe? With the thickness it seems pretty sturdy, but it is very heavy too.

Outside


Inside


I'm not looking for a Roll Gage, just to add on to or replace my sport cage. But I'd like to be able to look at a cross section of a piece of pipe and be able to tell something about it. Thus the above drill stem as an example. Just happens to be what I'm currently working on, and it made the lights in my head turn on for a glimmering moment.

 

[Lumpy Grits]

I want'd a 'cage' and used certified DOM 4140, 2"X.125 wall.
Remember the outside of the bend becomes very thin.
YES-HH did a great job with his front tie in section.
You don't want to weld anydangthing that's been galvanized. The fumes WILL kill you if you don't remove the gal. with acid.
What oil pipe I have worked with, was very weldable.
I think it's way overkill for your needs.
LG

 

[mriplaybass]

Simply put, tube is measured by OD, pipe is measured ID. Tube wall thickness is measured by a number, as Lumpy stated 2"x.125". This tube is actually 2"OD with a .125 wall thickness. Pipe wall on the other hand is referred to as "schedule". A 2" pipe would actually have an OD of 2.375", and if it were schedule 40, the walls would be .154", schedule 80 would be .218"
Tube, to the best of my knowledge is stronger. I am not sure, but I don't think that organizations such as NHRA allow roll cages to be made of pipe.

 

[IOPort51]

ERW 1.5x.95 used in stock cars.

 

[PistolDave]

I have used a fair amount of 1.75x0.120 DOM tubing in my jeep, it seems to be a pretty common size for general roll bar use. In this picture my tire carrier, shoulder harness bar, spreader between front and rear hoops, and windshield bars are all made from this size. The larger tubing bar is 3.0x0.095 tubing I believe and came with the jeep. The JD2 model 32 bender with SWAG Harbor Freight air/hydraulic upgrade makes pretty quick work of the 1.75 tubing.

 

[Lumpy Grits]

ERW 1.5x.95 used in stock cars.

"ERW"?
LG

 

[007]

Electronic Resistance Welded

http://metalsupermarkets.com/blog/difference-between-erw-dom-and-seamless-tube/

...I didn't know either, but found that out on the site above...

 

[Lumpy Grits]

Electronic Resistance Welded

http://metalsupermarkets.com/blog/difference-between-erw-dom-and-seamless-tube/

...I didn't know either, but found that out on the site above...

THX-That's a new one to me.
LG

 

[Hedgehog]

Remember a pipe bender won't do a good job on tubing. The dies are different. If you could get tubing dies for a pipe bender I can't see why it shouldn't work.

Some well pipe is brittle ,it would make me nervous for something like a cage.

As you probably remember I used pipe from "Metal Supply Co." to make my cage. MSC also carries a large supply of Chrome Molly, Dom and iron pipe. I went cheap on the tire carrier with pipe, but the stuff is much heavier than I expected. For the cage 2" and 1.50" mostly. For chamfering the but joints hole saws in a drill press worked well. When two pipes were welded together inside sleeves were used. This allowed higher working temps for nice deep welds and the pipe was easier to handle with some inside support.

 

[tarry99]

This question has been asked and answered many times.............

If you value your body and want a level of protection..........DOM tubing is the bare minimum you should use..........DOM is the by product of ERW tubing after it has been "Drawn over a Mandrel" which shapes and smooths the tubing while also making it stronger.................Chome-Moly is your lighter weight and stronger alternative. These are the only two choices for most organized Racing.

Water Pipe and any other Low yield strength materials should be avoided.

 

[Lumpy Grits]

Tarry99-THX for the details about ERW.

LG

 

[Hedgehog]

Opinion Thread! We've been over this an over this. We are not traveling at 200 mph, we don't need a controlled energy absorbing crush. We generally need something to protect the vehicle from damage at slow speed. I do not and will not believe that we need NASCAR roll bar type protection where they done give a darn about the vehicle, a NASCAR roll cage is designed to destroy itself to protect the driver. Those that don't believe that simply won't, it's all over the internet where rollbar/rollcage/sport bar construction is discussed. Also, if you don't know how to weld it, chrome molly is /dangerous.

 

[Woolyworm]

Mine is 1.75" HREW. I classify it at a branch deflector and CB mount. [emoji12]


Wooly

 

[Lumpy Grits]

"Also, if you don't know how to weld it, chrome molly is /dangerous"

Anydangthing that a person tries to weld. Who doesn't know how to weld, will be dangerous.
I have found C/M to be very easy to weld using my wire feed welder with flux-core wire.
LG

 

[007]

Opinion Thread! We've been over this an over this. We are not traveling at 200 mph, we don't need a controlled energy absorbing crush. We generally need something to protect the vehicle from damage at slow speed. I do not and will not believe that we need NASCAR roll bar type protection where they done give a darn about the vehicle, a NASCAR roll cage is designed to destroy itself to protect the driver. Those that don't believe that simply won't, it's all over the internet where rollbar/rollcage/sport bar construction is discussed. Also, if you don't know how to weld it, chrome molly is /dangerous.

Agreed. For some of the tubs I've seen, PVC would be an inexpensive alternative ;-)

 

[tarry99]

Never cease's to amaze me when someone comes up with the same old basic excuse about these Jeeps not being a Race Car nor do we need protection for 200 mph.............Will I can surely agree that they are not Race Cars nor will most ever see 200 mph...........but to all the Soothsayers out there one thing is for sure........"You can be just as dead at 200 MPH as you would be at 5 mph in a roll over down a hill or into a ditch!"

My point is simple..........if your going to add steel to your ride to resemble something that looks or acts like a Roll Bar or down tubes or a rear hoop , why not use the correct methods along with the correct tubing?.......the time bending and fabricating the stuff is basically equal........and the cost of the correct tubing is only a fraction more of what the junk pipe is?......It amazes me that this is even a valid discussion when your talking about youself or your family or passengers safety.


And to quote LG: "Anydangthing that a person tries to weld. Who doesn't know how to weld, will be dangerous.

 

[Peanut Butter]

Thanks for all of the replies. I really didn't want to bring the old argument up about what tubing should be used, how it needs to be welded, or how a roll gage is put together..................I really just wanted to be able to look at a piece of round metal and be able to tell weather it was pipe or tubing. I think I found a couple of answers that helped with that. Thanks, be safe and have fun all.

 

[IOPort51]

THX-That's a new one to me.
LG

ERW is a lot less expensive than DOM. It is the same alloy just has a seam bump on the inside.

If I was going to hit a wall at 200 mph I would use chrome molly. I have never cut one but I doubt the original is DOM.

I have a place that builds stock car frames that sells me tube at a good price and charges me $8 a bend. I would like to have a tube bender but just don't use one enough.

I also cheat and build my bar like a pipe welder would. I have the bends made to the angle I want and tig. weld in the strait sections. Then the weld is ground/sanded smooth.

 

[mriplaybass]

I also cheat and build my bar like a pipe welder would. I have the bends made to the angle I want and tig. weld in the strait sections. Then the weld is ground/sanded smooth.

Done it that way myself! Though I prefer to make the bends correctly the first time, and have as many tubes without splices as I can manage, it sure makes a lot less waste if you have the inevitable "OOPS!" by just splicing straight sections between the bends. I like to use a piece of tubing that will fit several inches inside the actual size tubing that I am using, drill holes in the larger tube, then rosette weld the holes. Then I do a full perimeter weld on the larger tube and grind it smooth.

 

[Hedgehog]

Sorry guys but Chrome Molly is well known for not handling welding very well. Many European auto manufactures of both motorcycles and cars prefer to glue their Chrome Molly tubing with double butted joints. CM and heat don't get along very well.

I don't use junk water pipe. I use the stuff that is DOM, but not DOM, it still has the weld bump in it and is very smooth. NOT strictly what most of us think of as black iron.