roll cage materials sched 40 pipe vs. dom

[CanMan]

You do know this thread has been dead for almost 3 years right?

:twak:

At least he searched, I guess. :dunno:

 

[Matt S.]

good info here too.

 

[flexy92xj]

Lots of factors to consider on this debate... but yes a roll cage can be built out of pipe with a HF bender and it will hold if the DESIGN is robust.

roll cage effectiveness is about 4 things... Design, Design, Construction, Materials.

I don't think anyone can make a strong argument that pipe is better than HREW or DOM tubing but it CAN work if used properly and will save a bunch of $$. It may not be the lightest, or the best in a high speed NASCAR style roll but it will take a heck of a beating if the geometry is right.

I have seen tube and pipe cages that I would not trust but I have also seen and built cages from both that stand up to all the abuse I could give them.

There are strong voices on this list that will always give the pipe is for poop or redneck cages replies but do your research and understand what you really need from a cage before designing and picking materials.

When in doubt let safety win in a decision over $$ or a time crunch.

 

[Matt]

Well mine if from the era of the thread so here you have it - still taking a beating and 8 or 9 rolls later (not to mention a fair bit of busted glass even with the exo...)

Matt (ps A-53 is the structural grade of pipe you need to ask for)

 

[tealcherokee]

i find it amusing that here brett is posting how pipe and the harbor freight bender suck, but now his cage is partially made from pipe and he used a HF bender

 

[Matt]

Come awn guys - we all know its just an ego thing... everyone just wants to be one of the cool kids so saying you used pipe just has a stigma attatched to it even if the engineering is sound...

 

[FiFo]

Personally I don’t see the point in building a cage out of pipe. My cage including front and rear bumpers is being made out of a combination of 1.5” DOM and 2” DOM. So far I have gone through 7 20 foot sticks of 2” and have 4 stocks of 1.5” waiting on the rack. Total cost in materials is probably going to end up less then $750 for all the tube. Sure using HREW would have made it slightly cheaper, and while I never priced pipe I’m sure it would have saved me even more. The thing is where safety is concerned why scrimp?

A few years ago a member of a club I belong to was in the wrong place at the wrong time when the wrong part decided to break. He found himself in what can only be described as a “hard role”, his CJ was totaled and they had to bring in an army Blackhawk to get him out. He survived and wheels to this day, but his new rig is built like a tank. Point is no one intends on a hard role, but when it happens is not the time to find out that pipe wasn’t strong enough, is your life worth a couple hundred bucks?

 

[Lee_N]

Looked up some specs for comparison -

Pipe 1 1/2 Sch 40 (A-36)-
Weight - 3.631 lbs/ft
Grade A - Tensile strength - 48,000 psi, yield strength - 30,000 psi
Grade B - Tensile strength - 60,000 psi, yield strength - 35,000 psi

DOM 1.500 X .140 wall (1018) -
Weight - 1.769 lb/ft
Tensile strength - 80,000 psi, yield strength - 70,000 psi

HREW 1.500 X .140 wall (1020) -
Weight - 1.769 lb/ft
Tensile strength - 50,000 psi, yield strength - 36,000 psi

As you can see: 1) tube is about 1/2 the weight, 2) pipe will bend easier than DOM, 3) DOM has the highest tensile and yield strengths, and 4) HREW is about the same strenght as pipe.

Lee

 

[FiFo]

Looked up some specs for comparison -

Pipe 1 1/2 Sch 40 (A-36)-
Weight - 3.631 lbs/ft
Grade A - Tensile strength - 48,000 psi, yield strength - 30,000 psi
Grade B - Tensile strength - 60,000 psi, yield strength - 35,000 psi

DOM 1.500 X .140 wall (1018) -
Weight - 1.769 lb/ft
Tensile strength - 80,000 psi, yield strength - 70,000 psi

HREW 1.500 X .140 wall (1020) -
Weight - 1.769 lb/ft
Tensile strength - 50,000 psi, yield strength - 36,000 psi

As you can see: 1) tube is about 1/2 the weight, 2) pipe will bend easier than DOM, 3) DOM has the highest tensile and yield strengths, and 4) HREW is about the same strenght as pipe.

Lee

Do you have the specs for 2" DOM? I'm wondering how much extra strength I'm getting building my cage with 2" instead of 1.5"

 

[Bender]

Lee,

You are correct with your comments when dealing with equal sized tubes of each material. However, much like how design is the most important factor in roll cage strength, the cross sectional shape of each member has more to do with it's strength than it's material.

In the examples you provided above the pipe is approx 5% STRONGER in bending than the DOM because it is actually larger...i.e. almost 2" in diameter compared to 1.5" in the DOM. As for shear strength the DOM would be about 30% stronger than the pipe.

Anyway, the point of the story is that design is the key and materials no matter how strong will not make up for a bad design.

 

[DirtyMJ]

Looked up some specs for comparison -

Pipe 1 1/2 Sch 40 (A-36)-
Weight - 3.631 lbs/ft
Grade A - Tensile strength - 48,000 psi, yield strength - 30,000 psi
Grade B - Tensile strength - 60,000 psi, yield strength - 35,000 psi

DOM 1.500 X .140 wall (1018) -
Weight - 1.769 lb/ft
Tensile strength - 80,000 psi, yield strength - 70,000 psi

HREW 1.500 X .140 wall (1020) -
Weight - 1.769 lb/ft
Tensile strength - 50,000 psi, yield strength - 36,000 psi

As you can see: 1) tube is about 1/2 the weight, 2) pipe will bend easier than DOM, 3) DOM has the highest tensile and yield strengths, and 4) HREW is about the same strenght as pipe.

Lee

Okay... Where'd you get the lb/foot info or did you calculate it? When I ran the numbers on 1.5" sch40 I don't think it come out to weighing that much - but I don't remember for sure.


And your tensile strengths are in PSI - which is relevent if both materials are of the EXACT same dimension. But it isn't because 1.5" sch40 is not 1.5" OD.


Unless I'm missing something here?

 

[Bender]

You are correct. 1.5" sched 40 is 1.9" in O.D. with approx 0.145" wall thickness. In bending it is actually stronger than the 1.5" DOM of the given material listed previously even though it's tensile strength is lower. The extra size adds considerable strength

 

[badron]

let me know if you find a roll cage builder that recommends schedule 40.
=========================================
You never will. Not because pipe can't do the job. The builder will cover his a$$ as much as he/she can. Using or recommending pipe, poop pipe puts the builder at a Addison risk in case of a law suit. As we all know the manufacturer of poop pipe do not recommend the use of it for shush things. So in turn any builder of cage takes all the reasonability apron himself incase of a bobo if poop pipe is used. The builder wants to be able to push the blain back to the pipe manufacturer. It don't have a thing to do with the pipe itself.
Why don't pipe manufacturer recommend poop pipe for things of this type? MONEY, MONEY, MONEY You simply don't pay for them to WANT to cover themselves. To pay for the insurance. The potential for law suits would be huge if all the poop pipe they sell could be used in high risk stuff. The cost of poop pipe would be considerably higher.
Half the reason things are done the way they are (in general) is to cover someone butt.
I just got a compression coupler to fix a brake line. The counter man told me they would no longer sell CC to fix brake or gas lines.
Fine give me one to fix a air line I told him. His a$$ was covered (more or less) and I got my compression coupler. This is the way of the world.

 

[Bender]

Pipe and tube manufacturers don't care how you use it...they have a given spec and their product must meet it. It's that simple. It's up the the end user to interprete that spec and use it accordingly. A tube supplier doesn't guarantee their tubes will work in a cage either. They can only guarantee it meets a metallurgical composition, a strength requirment, and a dimensional tolerance. Pipe is cheap beacause it has a greater variance in tolerance and composition. Tube is more because it has tighter tolerances and composition requirements.

 

[DirtyMJ]

Pipe is cheap beacause it has a greater variance in tolerance and composition. Tube is more because it has tighter tolerances and composition requirements.

Not really. Yes, the high end tube (DOM, CREW) is more money partially because it is of a greater quality. It also has a lot to do with supply and distribution though. DOM tubing isn't used for much - race car/buggy chasis, aircraft chasis, and axle tubes... Hence most steel suppliers don't stock much (if any) and it costs them an arm and a leg to special order it and they pass that onto you by charging an arm, leg, and a left nut.


HREW tube and ASTM A53 pipe are pretty much the same price - the pipe is really only cheaper because it is more common. They're also made to similar tolerances, have similar composition, and use the same process.


The funny thing is that in reality, both HREW and Pipe suck. Sure, you can make a cage with them... It is the cheapest route. I'll probably do it when I get around to it.

 

[gunruner]

my .02 i am a fitter and work with sch40 all day . and to me it is fire sprinkler pipe that is why they make it . and the quality sucks i have seen 1" break off frum a lift hiting it and 1 1/2 bend all to easy . and in some cases seen a 2' section leak water frum the seam that you cant see with a visul inspection . i whould not use it in a cage and i can git all the pipe i want for free . maby in a bumper or rock rail where life safty is no so much an issue yes because a peace of 3" is stronger then our stock bumpers .

 

[yogi]

good place to my pipe or DOM

http://www.metalsdepot.com/index.phtml

 

[FIREBLADE]

I use Ballistic. They can cut to your lengths and its cheap.
http://ballisticfabrication.3dcartstores.com/DOM-Tubing-by-the-foot_c_18.html

 

[AJsArmor]

I see no problem in using pipe for EXTERIOR pieces such as guards, sliders, exo as people have done for years. Sometimes it's easier for guys to get their hands on cheap/free, the biggest downside is the weight though.

For interior cages I wouldn't even consider it and flat out refuse to build one for a customer no matter how much they are paying me. HREW or DOM only. I don't see any valid reason for using pipe over HREW on an interior cage at all, especially beings that the cost is nearly the same and in some cases HREW is cheaper. HREW for a well designed interior cage is definitely the way to go, or if you have some deeper pockets, DOM. Oh and I usually use 1.75x1.25 and .95 for cages.

 

[sgtmack]

And let me know you fixed your brake line with a compression fitting before you wheel with me. Because you won't wheel with me. I've seen what happens when one fails.

If a majority of peple with fab experience tell you it's not a good idea, maybe it's not a good idea.

And yes, I have seen 1.5" black pipe I could bend by hand. Use tube.