Cage material, how bad is sched 40 pipe?

I understand that a proper cage should be DOM or chromoly, and budget builds usually ERW or HREW is sufficient...

...but is there ever a scenario where schedule 40 pipe would suffice? If the purpose is purely for structural rigidity and you aren't planning on having it save your life?

I've read through a lot of offroad builds and it seems to be evenly split between "i'd never use schedule 40 pipe" and "it's plenty strong and cheap to boot!" i know it's quite a bit heavier than HREW (probably why the 4x4 world embraces it) and for the same 1.5" name theyre really not the same size. so i'm familiar with the differences between materials , i'm just wondering where this group draws the line.

what says GRM?

No way

I think "cage" implies rollover protection of some sort.

Welding a tie bar between two shock towers? Yeah, sure, better than nothing.

Over my head? Never.

As some say, pipe is for plumbers. Pipe tends to be more brittle - not really a trait you want for cage purposes.

What's your noggin' worth?

No

4wd = slow rollover onto a tree, boulder or some such item (generally)

Trackday = stupid fast into a wall or other car, possibly backwards or upside-down.

No way in hell I'd ever use sched 40 water pipe for a cage that I hoped would save my life.

You could use it to build a jungle-gym for your kids.

Shawn

grab a piece of the water pipe and a piece of DOM tubing.. hit each of them with a large hammer. decide which one you'd rather have protecting you in the event of a violent rollover..

Depending on the answer you're looking for, you're probably asking the wrong crowd.

Pipe cracks when stressed, which means its sharp bits are now threatening your soft bits. Real cages are made out of the materials they are for a reason.

Jay wrote: Pipe cracks when stressed, which means its sharp bits are now threatening your soft bits. Real cages are made out of the materials they are for a reason.

This would be my concern too. Even if not using for safety purposes, the side effect is that sch 40 will likely make the car way more dangerous.

Search for a article by Doug Gore when he was with Speedway Illustrated. Doug did some very through testing.

ERW is not that much more and is really fine, Carol Smith said that one of his biggest regrets was saying not to use ERW. The ERW he used in the famed cage that split was foreign and defective. Todays ERW is goes through some very high quality inspections.

I would use PVC, it's much lighter and gives a bit before it cracks.

Zomby woof wrote: Depending on the answer you're looking for, you're probably asking the wrong crowd.

haha i'm not really looking for a specific answer, though the consensus thus far doesn't surprise me at all, just thought i'd float the argument i came across in front of a more like minded bunch of carfellas. i was honestly a bit surprised when the guy told me that's all he uses building rollcages as i'd never heard of it for this application before which prompted my researching the subject.

i've seen a pvc cage too. it was almost as awesome as the glowing stripper pole in the middle of the car.

im confused. Are you planning on using schedule 40 seamless A106 pipe or are we talking some sort of galvanized plumbing pipe?

i wasn't planning on using pipe for anything, i just came across a guy that uses it for all of his builds, from mud bog trucks to buggies.

i dont think he's talking about some brittle galvanized plumbing pipe but rather from what i've seen from pictures of his builds i'd guess its the a106 type. he says it bends easily, welds well and from talking with him it didnt sound like he's had any failures. he said it's steel not some iron product.

Ppppfffft. That stuff is way too heavy. For the same strength, lighter weight and ease of installation I'd go with PVC.

WilberM3 wrote: i've seen a pvc cage too. it was almost as awesome as the glowing stripper pole in the middle of the car.

He prolly means ERW tubing... not pipe.

I once saw one that was made from exhaust pipe. The tech inspector found it with a ball pien hammer.

You'll find some ratty local oval enduro cars fabbed up with schedule 40. I've also seen square stock welded at 90 degree angles. I wish I had pictures, but alas..

Schedule 40 black pipe is a ERW but not roll cage material. ERW carbon steel tubing in 1.5 or 1.75X .095W is economy class regs but not SCCA or NASA. GRMers take it from there.

Hell to the no.

You're gonna need to do more research into what KIND of pipe.

I've got a pile of "pipe" (at least that's what most people would call it) behind my shop. It was used as steam piping in a military installation.

It's DOM tubing. Just because it was pulled from a dumpster and used for "plumbing" doesn't make it wrong.

However, galvanized pipe is wrong. So is most black iron- it is not drawn over a mandrel, there is a joint along one side which is welded.

The failure will be in the weld and in the inconsistent wall thicknesses and weld quality.

WilberM3 wrote: I understand that a proper cage should be DOM or chromoly, and budget builds usually ERW or HREW is sufficient... ...but is there ever a scenario where schedule 40 pipe would suffice? If the purpose is purely for structural rigidity and you aren't planning on having it save your life? what says GRM?

Even if that is the only intention of the pipe, I would consider how it's being loaded and impacted. Would the structure of the pipe be more than it's ability to crack?

I almost think one still needs to build in some decent degree of flexibility, just so that the structure doesn't tear apart or crack.

Then again, MIG welds are not known for being the most flexible things in the world.

(roll over structure wise- I agree that the fracture resistance doesn't measure up).

So, can you make, say, a strut bar out of it? hmm..