I've decided that I want to go full exo. I saw the thread on the price of DOM tubing and now I'm all confused. What are the differences in DOM, HREW, and erw. Thanks guys.

HREW, hot rolled electric weld
DOM, drawn over mandrel (aka seamless)
I'm not quite sure how much the process increase the strength of the tube but it increase the price of the tube by about 3x's, I've heard about 10%.The only tube work that we've had to do in DOM is SCCA sanctioned rally cars. That's kind of why alot of people think it's not really needed.

Ask some of the metal guru's

Thanks, fatkid. Name some of the metal gurus now. I'm assuming you mean people on the board.

Tin Bender is one

Sorry, here's the long version.......

This grade of mechanical tubing is the fifth of six types classified in ASTM A513. Produced from steel strip by cold forming, electric resistance welding (E.R.W.) and cold drawing to finished dimensions, D.O.M. is the most versatile and widely sold mechanical tubing grade. With an appreciation for the product's flexibility, the reason for this is easily understood. D.O.M. can be produced with outside diameters as small as .125", as large as 15" and everything in between. The wall can be as thin as .010" or near .700" thick. Carbon chemistries range from A.I.S.I. 1006 to 1060. A variety of thermal treatments can be applied to alter the mechanical properties and machinability. The E.R.W. process guarantees the weld to be as strong or stronger than the rest of the tube body. The origin from flat strip results in a more concentric product than cold drawn seamless.

D.O.M. is used for a tremendous variety of machine parts where closer tolerances and higher mechanical properties are needed. Hydraulic cylinders, spindles, jacks, rollers, motor housings, elevators, air hammers, and shafts are just a very few of the applications utilizing D.O.M. tubing. :D

"CDSM"...............

"Cold drawn" as it is often called, is the precision half of the ASTM A519 specification. Once the dominant type of mechanical tube in the market, cold drawn seamless now plays a reduced but still important role. While D.O.M. has replaced seamless in nearly all standard shelf sizes common to both products. Cold drawn seamless is produced by the piercing method. A heated billet moves through pressure rolls as it is driven over a stationary mandrel to produce a hot finished seamless tube. This hollow is then cold drawn through a die and over a mandrel to precision finished dimensions. :D

4130 Tubing is often referred to as "Chrome Molly" tubing. This jargon term is derived from the chromium and molybedum concentrations present in the metal itself, which run in the area of .80-1.10 for Chromium and .15-.25 for Molybedum.
"Chrome Molly" tubing or 4130 Tubing is best for applications where a high strength to weight ratio is needed or desired. Typical tensile strength for 4130 is approximately 90-95000 PSI.
BUT a "drawn" tube OR "Welded" tube will offer a close 75,000-85,000 tensile.
AND with a ERW HERW you don't have to worry about Relieving your joints.



Now with that said, .250 wall is WAYYYYYYY overkill for a CAGE!!!! and HERW .120 wall is fine....:bender:

Broken down version.........

moly is cool, but a BIG pain in the ass....

DOM is cool, but WAY to much $$$...

weld'd is PERFECT for make'n cages and stuff, just keep the seam inside the bend to be x-tra safe....

Here are some more useless specs.....

ASTM A513 Type 1
Hot Rolled Electric-Resistance Welded (ERW) Carbon Steel Mechanical Tubing

ASTM A513 Type 2
Cold Rolled Electric-Resistance Welded (ERW) Carbon Steel Mechanical Tubing


ASTM A513 Type 5
Drawn Over Mandrel (DOM)

ASTM A513 Type 6
Drawn Over Mandrel Special Smooth ID (SSID DOM)

ASTM A512
Cold-Drawn Buttweld Carbon Steel Mechanical Tubing

ASTM A519
Seamless Carbon and Alloy Steel Mechanical Tubing

Just let me know when to stop!!!!

*deep breath*


ERW pipe is made from strips of hot-rolled steel, which are passed through forming rolls and welded. While seamless pipe is traditionally stronger and more expensive than ERW pipe, ERW technology is improving and the technique now accounts for approximately 48% of annual tonnage shipments of oil country tubular goods :D

SEAMLESS PIPE (SEAMLESS TUBE)
Tubular product made from a solid billet, which is heated, then rotated under extreme pressure. This rotational pressure creates an opening in the center of the billet, which is then shaped by a mandrel to form the pipe or tube.

The metal guru has spoken......

Can I stop now?:D

Originally posted by Tin Bender
Can I stop now?:D

nope, sorry :flipoff2:

a guy could get a education here thanks Mr Bender....:D

Like I said, :)

Tin Bender,
Thanks for answering this newbies questions. Next one though. I have decided to go full exo. Also, I want to cut the back into a flatbed. Well, me and my room mate are having a disagreement on the diameter of tubing to use. I was thinking a full 2". He says 1 1/4" is good enough. Your thoughts?

I was told almost the same thing,and was con vinced enough to buy the dies,now I just have to use them....:D

Going exo is a big step.... It's alot of work but well worth it in my opion..

Frosty rolled twice on bald mount'n on LeRoys first trip out!!! (not flops, complete rolls) Just to "test" the new exo out. All I can say, is he drove it there on the HWY, and he drove it back home, windshield intact and the cage not completely finish'd... (it needed some 1-1/2 brace'n in the rear)

Why would you want to go with 1-1/4?? Your not give'n up more than an inch and a half in width so that wouldn't be it...
Your not give'n up much in the way of weight...
In my opion, 1-1/4 is WAY to small to LOOK good...
It's not as strong as 2"...

If 2" just seems to big, I wouldn't go ANY SMALLER than 1.5 x .120 DOM or 1.75 x .120 weld'd...

The most important thing is to remember to cross brace right behind the cab to the FRAME...(99% of "rolls" are sideways)

And gusset the A-pillars to help the front to bach shift..

DON'T build your exo to keep the body from get'n dented, build it to keep your head off the rocks:D:D:D

people do thing different and thats great!!! If everyone were the same life would suck!!!

The 2" we used for the sammy took a hard hit before it was even done and it didn't even tweek in the slightest bit.

Thanks for the input guys. I'm going to bed now. Look for more newbie questions tomorrow or the next day.

TinBendy,

You rock! What would you say are the most common flaws in an exo cage? not enough bracing for lateral rolls, not enough against front-to-rear forces?

I guess I'm asking... What are the things you almost always see WRONG with the exo-cages people do to their own rigs in their shop?

IMO...... and it's just that..

I DON'T want to come across like some smart ass know it all, and if I have, i don't mean to...

It's something like "DRM phobia":D:D:D

IMO, the biggest thing is the lack of cross lateral cross brace'n...
I know some guys can't afford to lose, or choose not to lose the space, like in FatKids sammy... that is why it's made of 2"x .120... Insted of 1.5 or 1.75 x .120.. It's a give and take..

Good mounts are another thing....
Go right to the frame if you can...
If not, make a DAMN good mount/standoff..
Kinda like "The house is only as good as the foundation"

And lastly, A little practice with the welder go's a LONG WAY......
take a bunch of scrap tube, and practice weld'n it up.. Most people can lay a damn good bead straight flat and level, but once out of position
:eek:

It's not hard, just get use to welding vert and over head, until you get comfortable.

Take your time, there is no race to get it together, and you'll be ALOT happier with the end result... :A cage you can be proud of, and one that you KNOW will take a good hit...

PS!!!!!
KNOW WHEN TO STEP AWAY FROM THE BENDER!!!! Do you remember EB BRONCO :eek:
Sometimes, it's easy to get carry'd away...:D:D:D

Yeah... I remember that jungle-gym Bronco. Hard to forget.

We need a "BoneHead 4x4 Discussion" forum for all the stuipd shitzu people do to build a rig. :D

Thanks for the reply. Good stuff... and I definitely understand DRM-Phobia. :laughing: :laughing: :laughing:

I would love to do an Exo cage on my tin top 86' but, How would you get good cross-bracing and still not penitrate the body, block the rear door or cross the windshield ?

Dave

Originally posted by Tin Bender
Just let me know when to stop!!!!

*deep breath*


:D

Couple more questions then.. I have friends that swear by their Sch40 black-pipe cages. I can agree that it's better than nothing, but I'd like some hard data to back up why TUBE is better than PIPE.

I haven't been able to find tensile and yield figures for Sch40 pipe yet.. got anything to use for comparison purposes?

Then my next question is for the engineers..

I think the overall strength of a tube is related to section-modulus, but I'm not sure how that's calc'd..

But my question is how tensile/yield figures are applied to OD and thickness to get an overall "strength" for a given chunk.

We all "know" that 2"x.120 1020 is stronger than 1.75 x .120 1020. but.. HOW MUCH stronger and in what fashion?

How about 2"x.120 1010 vs. 1.75x.120 1020?

4130 is stronger, so you use less of it, for the same strength and less weight.

How do you calc where the "even strength" point is? 1.75x.095 4130 = 2"x.120 1020?

Could I use 2"x.188 1010 in place of 2"x.120 1020?

What does it all mean!!! :D

I took EE and now Software Engineering.. I don't need to know all of the nitty gritty details, but I'd like to have more than the average redneck's understanding of it all..

My Machinery Handbook doesn't seem to address (or I haven't found) these types of questions..

I'm sure there are some specs somewhere, but when it's made into a CAGE, there is NO WAY to figure how hard, fast, or where it's gonna take the load..

I do understand your quest for knowledge though..

But, Ask your freinds the next time you see them...If PIPE is so good, why is it that you can't make cages out of it for any major motor sport?

Originally posted by Tin Bender
I'm sure there are some specs somewhere, but when it's made into a CAGE, there is NO WAY to figure how hard, fast, or where it's gonna take the load..


Yeah, I have no desire to start drawing vectors or anything! but even something to the effect of..

Laying a 2"x.120 1010 tube across a 10ft span, it'll support 100lbs in the center.

2"x.120 x 1020 tube across a 10ft span will support 200lbs in the center.

1.75x.188 1010 tube across a 10ft span will support 150lbs..

Or maybe it's all just a "pipe dream" :laughing:

But, Ask your freinds the next time you see them...If PIPE is so good, why is it that you can't make cages out of it for any major motor sport?

That doesn't work. They wrote the rule-book for our state 4x4 sanctioning body.. and it calls out "1 5/8 OD, Min. Sch40 wall thickness"!

When pressed.. "We don't go as fast as [insert favorite example]"


I know I've seen over 65mph in the dirt n' over jumps.. and my rig'll do more if I can get it enough carb (which involves machining a 2bbl intake into a 4bbl, or a sheetmetal intake since a 4bbl was never offered for the IH 304). Mine isn't one of the faster rigs running, either.

*I*'m starting to feel uncomfortable with the Sch40 "cage" I inherited..

In any case, I'll continue my quest for solid #s to support "1010 tube is better than any Sch40 pipe"..

1.5 Sch40 is selling for just over $1/ft locally. I finally tracked down a supplier than can get me 2"x.120 1010 tube for $1.67/ft..

If I can show that 1010 is 2x (or 1.5x or..) stronger than Sch40, I think I can make my case. :)

Even if we really don't "need" more than Sch40, who would argue that 2x the protection for $.50/ft more isn't worth the price?

$170 instead of $120 for a jungle-gym cage..

And since I got railroaded into "Race Rules Chairman" this year, I might stand a chance of getting some points across. :D

Lemme see what I can dig up...:D

I’ll insert this point to begin with: I know very little about designing/building roll cages. However I have more than a passing familiarity with pipe/tube and the structural uses of it. First some specs: 1010 CREW/HREW tube yield 40ksi, tensile 55ksi. 1010 ERW tube yield 32ksi, tensile 45ksi. 1018 tube (CDS) yield 60ksi, tensile 80ksi. 1018 tube (HFS) yield 35ksi, tensile 60ksi. 1020 tube DOM yield 70ksi, tensile 80ksi. A53B pipe (SEAMLESS) yield 35ksi, tensile 60ksi. A53A pipe (ERW) is normal everyday black iron pipe, is not recommended for cold bends less than 5x the pipe diameter is rated at yield 30ksi, tensile 48 ksi. Almost all industrial uses of pipe as a structural member (The only area where I have any expertise) calls for a minimum of A106B (yield 35ksi, tensile 60ksi) where there is an endangerment of life. These applications do not take the weight of the assembly into account. For example :” Laying a 2"x.120 1010 tube across a 10ft span, it'll support 100lbs in the center.” It will support approx 650#, assuming that you used 1010 CREW/HREW, “2"x.120 x 1020 tube across a 10ft span will support 200lbs in the center.” It will support approx 950# in the center. Using 11/4” A53A pipe( 15/8” OD), with a wall thickness of 0.125” (SCH. 40 is 0.140”, but I don’t have the information I would need to do this calculation at home with me ) would support approx 425# in the middle of a 10ft span. All of these calculations are for reference only, are based load at failure(tensile) not yield and may not be exact due to the fact that all of the information was soft converted from metric. Also keep in mind that pipe is designed for fluid loads I.E uniform internal stresses, whereas tube is designed for external, hopefully uniform stresses. Basically you probably could make a rollcage from pipe that would be as strong as tube but it would be much heavier and be more difficult to be sure that your bends were sound. It would be like having 44” Boggers on a daily driver – It works, but at what cost.

Tin Bender, you rule ! :beer: its good to hear real FACTs on stuff like this.


Here is somthing real simple to get loads of ideas on cages. Go buy a few issues of circle track magazine, loads of ads for boughten cages to full chasis. You can easily see what kinds of designs they are using, and adapt them to yours.

FWIW: I have a JD2 bender with a 1.5" and a 2" die ill be making my exo from 1.5" .120 (~$1.35/ft) 2" die works great for exhaust stuff :-) I got the rail part on the bottom done.

I too liked the look of the flat bed and will be doing somthing like that. I have measured up my current top and can cut and re stitch it to make a nice back window set up that zips down. Ill just use some regular snaps on the sides to seal it.

I did get my new (to me) 32" TSL tadials :-D this past weekend. What a pain it was dismounting them by hand (ok we used my new harbo freight manual tire machine $35 yahooo) but we made good time after the first few....


--anyway post some pics when your done! I will when I make some progress on mine.

-mike

Wow, Jason GOOD STUFF!

Bender, you da man! I can't wait to get my cage built. I hear you're quite handy with a sawzall too.

Riiiiiiiiiiiiiight. :rolleyes:

It's not the welder and the JD2 that are the tough part... it's the SawZall. :flipoff2:

just out of curiousity ... tin bender do you have a college degree and if so in what? i would address the same question to jasonmt. i am in no way questioning your guy's informational validity, just curious because im in school for mechanical engineering and it intriques me that you guys know all this information. thanks for all the information ... it has been very helpful. i am planning on building an exo myself, and a friend is looking into building a cage for his commando and these are issues we have been discussing. Thanks again.

I'm not trying to piss anyone off here, just asking the question.
What are the faults of "Pipe" . alot of people use it, and you hear horror stories about it, but is this all just urban legand? Does anyone have bad example pics of 'Pipe' gone wrong? We hear that it is fragile, and splinters, and that pipe benders kink the pipe, but I have not seen any proof to this. Is anything better than nothing? Or does pipe pose a risk? Not everyone can afford, or wants to buy a JD2 bender. I know everyone says" why don't they use 'pipe ' in NASCAR? But I don't think our trail rigs are hitting a brick wall at 200 mph. These are simple rolls, flops, endoes, and back flips. I am not trying to open a can of worm , just have these questions answered.

Originally posted by mudlite
These are simple rolls, flops, endoes, and back flips. I am not trying to open a can of worm , just have these questions answered.

The more serious rolls I've seen haven't been flops, and tip-overs.

They're OH SH*TS on the highway...

Scenes like THIS:

http://tigger.tmcom.com/~tsm1/scout/jpg/spirit76/vid_caps008.jpg

The only reason my friend walked away (and ran track the following weekend) was the factory installed 2" HREW bolted-to-the-body rollbar. It was part of the special Spirit of '76 package that made this a rare Scout before the roll.

He only went over on his side, BTW.

At 60mph.

Nodded off for just a second.

The door, A-pillar, rocker, and driver's floor were not attached to the Scout when I went and picked up the wreck to bring home so he could come back later and salvage what he could.

The motor, trans, xfer, rear axle, and tailgate are all useable. The rest? Well, there are some door handles, window winders, marker lights.. but not a lot else.

More pictures of the wreck (http://tigger.tmcom.com/~tsm1/scout/jpg/spirit76/pics.htm)

Now.. about that "NASCAR goes 200mph and we don't" bit...

I'm not building a cage in the case that I am Stupid enough to fall asleep at the wheel. I am building one for the trails. I am aslo not talking about stock roll bars saving people lives. I was asking for proof that pipe DOESN'T work.:rolleyes:
Your buddy was doing 60, that is considerably slower then 200.
Whats your point????????????????:flipoff2:

Originally posted by mudlite
I'm not building a cage in the case that I am Stupid enough to fall asleep at the wheel.



No one PLANS to fall asleep at the wheel.. or to hit a patch of ice and go sideways.. then hit a patch of dry.

Or to have someone run a light and knock you over.. or an Elk step out in front of you and you swerve to avoid it, or...

Street is far more dangerous, and much faster, than the trail.


I am building one for the trails.


Will you be trailering it?



I was asking for proof that pipe DOESN'T work.:rolleyes:


I didn't take pictures of the pipe cage that collapsed in Powell and sent a guy to the hospital with a broken collarbone and concussion (and a cracked helmet)..

I do have pictures of a pipe cage holding up... to a mild flop.

http://tigger.tmcom.com/~tsm1/scout/jpg/racing/4_6_2001/snap-default-20010409-014140-1.jpeg
http://tigger.tmcom.com/~tsm1/scout/jpg/racing/4_6_2001/snap-default-20010409-014140-2.jpeg
http://tigger.tmcom.com/~tsm1/scout/jpg/racing/4_6_2001/snap-default-20010409-014141-1.jpeg
http://tigger.tmcom.com/~tsm1/scout/jpg/racing/4_6_2001/snap-default-20010409-014149-1.jpeg


Your buddy was doing 60, that is considerably slower then 200.
Whats your point????????????????:flipoff2:

Point is, 60 is WAYYY less than 200.. and he still royally fawked his rig up, and was lucky he walked away. 200mph doesn't need to be the determining factor. Just 60mph will ruin your day.

I realy don't see how this is answering any of my questions?
So when your friend fell asleep at the wheel, did he have a cage?
Or was it just the factory bar? What does this have to do with PIPE????????????????

Originally posted by mudlite
I realy don't see how this is answering any of my questions?
So when your friend fell asleep at the wheel, did he have a cage?
Or was it just the factory bar? What does this have to do with PIPE????????????????

He nodded off with a factory 4pt bar bolted to the body.

That point is that 2" HREW to the tub saved his life.

The Bronco rolled with a pipe cage and survived.. point is, pipe DOES hold up in some cases.

I don't have an example of a pipe cage rolling at 60mph.

Nor do I have pictures of the failed pipe cage last summer.

Further, TUBE is KNOWN to hold up. Pipe is still in question.

TUBE isn't that much more expensive than pipe, so what's the argument for using pipe instead of tube?

Then again, you only need to invest as much in a cage as you think your noggin is worth.

Sometimes I want to just let the folks with muffler-tubing cages go ahead and run it.. and do the rest of us a favor.

There was a thread a while back (do a search!) where the strengths of pipe vs. tube was listed off, and a rough comparison of how much weight each would hold in a given situation..

Tube seems to be the hands down winner in every category...

Locally, 1.5" ID/1.9" OD Sch40 blackpipe is $1.40 a foot.

2"x.120 1010 mild steel tubing is $1.67/ft.

$.27 / ft more..

I have never said cost was an issue in the material. But how much is a TUBE Bender compared to a pipe bender? I don't plan on building too many cages in my life, so it seems silly to buy a tube bender, when I can buy a pipe bender at next to nothing.

Do I trailer my rig , yes. Am I going to drive it at 60 mph? Not often.

My question still stands show me how PIPE has failed. I don't want text book point loads, or bending moments. That is good for structural engineering, not real world mechanics of wheeling.

Given a proper design, with diagonal braces, gussets, and PROPER welded joints, will a pipe cage stand up?

Originally posted by mudlite

My question still stands show me how PIPE has failed. I don't want text book point loads, or bending moments. That is good for structural engineering, not real world mechanics of wheeling.

Given a proper design, with diagonal braces, gussets, and PROPER welded joints, will a pipe cage stand up?

A pipe cage failed when a guy did an end-over. It folded over sideways and the roof of the rig collapsed.

Can't say just why it failed - poor design, poor welds, or poor material. I had other priorities at the time. ;)

No doubt that in most cases a properly built pipe cage will be fine.

OTOH, the pipe cage would be heavier than tube, which means you need a stronger cage just to support the cage weight. :)

And pipe benders like to kink the pipe in the bends, which is a big no-no for strength.

Of course, you could always buy a JD2 and order a Sch40 die..

Originally posted by mudlite

Given a proper design, with diagonal braces, gussets, and PROPER welded joints, will a pipe cage stand up? [/B]

From Jasonmt's reply:
1010 CREW/HREW tube yield 40ksi, tensile 55ksi. 1010 ERW tube yield 32ksi, tensile 45ksi.

A53A pipe (ERW) is normal everyday black iron pipe, is not recommended for cold bends less than 5x the pipe diameter is rated at yield 30ksi, tensile 48 ksi. Almost all industrial uses of pipe as a structural member (The only area where I have any expertise) calls for a minimum of A106B (yield 35ksi, tensile 60ksi) where there is an endangerment of life.

Yes, with proper design pipe will suffice, but it will weigh more than tube for an equal "cage strength".

Originally posted by mobil1syn
just out of curiousity ... tin bender do you have a college degree and if so in what? i would address the same question to jasonmt. i am in no way questioning your guy's informational validity, just curious because im in school for mechanical engineering and it intriques me that you guys know all this information. thanks for all the information ... it has been very helpful. i am planning on building an exo myself, and a friend is looking into building a cage for his commando and these are issues we have been discussing. Thanks again.

It is always wise to question validity, and I for one will be happy to explain my education/practical background for you. this is from a previous post:

"Paul - working at the Shell Upgrader in Ft. Sask. right now. Don't know how to describe my job. I have my Journeyman welder ticket, including ABSA certification in 4 processes and have my level 3 inspector certs. Also a Journeyman Steam/Pipefitter, and working on my Engineering Degree. On this Job I started out as Underground QA/QC inspector/civil coordinator. After we were done the UG piping I became our units piping structural field engineer, and as of Monday I am the piping systems turnover coordinator. Basically I run around like the new guy in prison trying to make sure that the different departments get along and everything gets done on time."

Basically a mix of field experience and school. I have about 80 credits out of the 120 I need for my degree, also Bsc in Mechanical Engineering, but I am now finding it VERY hard to justify going back to school to finish my degree. The companys I have worked for would rather have someone with field experience and a trade background than someone with good paper, and they pay accordingly. You will find a big part of school/work is just finding the relevant information and applying it.

You guys are fascinating! All this talk makes me want to pull out the engineering books and do some cackilatin'.

I am not a tubing or pipe expert per se, but I do know a little about structural engineering. IMHO. Pipe is fine for what we do. It generally has thicker walls and weighs more per foot than tubing. When you are trying to build a "system" like a roll cage, often times the thickness of the tubing, and even the size is over rated. When building a cage, the shape of the cage and the placement of the members is the most critical issue, followed by the diameter of the tubing, and lastly by the wall thickness. Using shorter spans, bends, gussets, and appropriate bracing allows you get the same effect (within reason) from lighter stock. I would guess that most cage failures could be prevented by either a little more bracing or a LOT heavier members.

That being said, to me a minimum wall thickness of 0.120" or so should be used to keep the tubing from being muched the direct impact of say a rock. I think the 1.5" to 2" sizes look better in most applications.

Likke I said, I ain't no tube expert, so I'll shut up now :D

I am accumilating all of the tubing (hoops had to be bent for me, no bender-yet) to build my cage starting tomorrow in my flatfender. I took some drawings of what I had in mind to my boss, Masters in Mechanical Engineering, been engineering for close to 50 years. This is what we came up with. A X as a structural member is the best if you don't know where the load is going to come from, like a roll. So I will have an x front to rear, and another X behind the driverseat. Along with a diagonal support behind the mainhoop.
As for rolling at 60 mph not pertaining to wheelin', ever seen some one roll back down a hill at even 20 mph? When they come down on a cage there can be more that 2x (or more) the weight of the vehicle on that spot. Also read that "A53A pipe (ERW) is normal everyday black iron pipe, is not recommended for cold bends less than 5x the pipe diameter is rated at yield 30ksi, tensile 48 ksi." (thanks again jasonmt) would put an acceptable bend in 2" O.D. shcd 40 at a 10" radius.
In the end it your life, is it worth $.50 a foot?

Black pipe rules! Long live Black pipe...:flipoff2: