Ok I know that alot of guys and even circle trac racers run erw my question is I found some sprinkler pipe left at one of our Job sites the other day when I looked at it, it was labeled ERW schedule 40 and the wall was roughly .125 other than the way pipe is sized to tube Meas. inner/outer is there any difference in the strength I have called a few local metal shops and all I get is the dear in the head lite look??? and yes I have searched but dont know all the lingo to quite understand it all Thanx Scott

Basically Is Pipe ERW = tube ERW or is there a stregth issue besides the usual sizing difference

There are different grades of pipe, some are better than others so I'm told.
I think a good grade of pipe is better than tubing in areas where there is a lot of exposure to rocks, i.e. rocker guards. It doesn't dent as easy. In areas where your life depends on it like roll cages, I think tubing is better as it will not fail catasrophically as pipe could. Pipe is more brittle. Also tubing has more of a crush zone to soften impacts. My .02

Ductile iron pipe is brittle; HREW pipe ain't. That's what the last expert I talked to told me, and he builds a lot of cages. Also, he didn't start spewing out warnings of impending doom when I told him I had bought the poor man's bender at Harbor Freight and would be building my cage out of pipe.

Basically, he told me HREW (hot rolled electrically welded) pipe is damn near the same thing as "tubing" just measured differently on the diameters. FWIW I believe 1.5" pipe has an OD of 1.99 inches, making it pretty damn close to 2" tubing.

Originally posted by Slinky
Ductile iron pipe is brittle; HREW pipe ain't. That's what the last expert I talked to told me, and he builds a lot of cages. Also, he didn't start spewing out warnings of impending doom when I told him I had bought the poor man's bender at Harbor Freight and would be building my cage out of pipe.

Basically, he told me HREW (hot rolled electrically welded) pipe is damn near the same thing as "tubing" just measured differently on the diameters. FWIW I believe 1.5" pipe has an OD of 1.99 inches, making it pretty damn close to 2" tubing.

Grey cast iron is even more brittle.

Ductile iron pipe (DIP) is not applicable to building cages.
The smallest size is 3-inch (I think without looking it up)
We use it all the time for water and sewer lines.
I don't think you can bend the stuff, I've never seen it done.
3-inch is rare, 4-inch on up is very common.

My biggest concern about pipe is you rarely can find out any info on the strength. They always have the manufacturer listed on it but good luck, the manufacturer only lists pressure properties, C-factors and stuff related to transporting stuff in the tube.

With tube you can find out what steel is used and how strong it will be.

On that note I'm planning to bring some pipe coupons in an throw them in the rockwell hardness tester and the brinnell hardness tester. Will give a good idea of what grade of steel.
Ken

Originally posted by Rockrat
Ok I know that alot of guys and even circle trac racers run erw my question is I found some sprinkler pipe left at one of our Job sites the other day when I looked at it, it was labeled ERW schedule 40 and the wall was roughly .125 other than the way pipe is sized to tube Meas. inner/outer is there any difference in the strength I have called a few local metal shops and all I get is the dear in the head lite look??? and yes I have searched but dont know all the lingo to quite understand it all Thanx Scott

Basically Is Pipe ERW = tube ERW or is there a stregth issue besides the usual sizing difference

Did it have any ASTM numbers on it, if so, I can probably look up it's yield and tensile strengths. And as JR said, pipe is generally a little more brittle, but it really depends on the grade. Generally off the shelf pipe (ie Home Depot) is probably not quite as strong as good ERW tube, and is significantly lower than DOM due to cold working of DOM, after welding though, I'd say they all are about the same.

Chad

PS, I know this has been gone over before, more than likely without a final answer, as I suspect will be the case with this thread

My biggest concern about pipe is you rarely can find out any info on the strength.

http://www.mk-corp.net/cgi-bin/ncommerce3/ExecMacro/MarmonKeystone/spec.d2w/report?FILENAME=/MarmonKeystone/images/A53.pdf

I understand Ductile and cast I would never use that, but this stuff we have is marked ERW right on it which I have never seen before On black pipe which in mop is just wrong I realy wanted to no is erw, erw or was there different grades of erw I know Chromoly is the strongest per say but also $$. My main cage is 2" .125 DOM but again I am going to add and finish the cage with 1-5/8 erw again cheaper then DOM and Chromoly price wise and Fine for a rollover in mop. I do believe that is what az is using on his rig.
Now Im rambling just needed to know if its ERW stamped and meets the Dimensions I want can it be used or is there different grades

I'm using the sprinkler pipe on my obstacle course rig. 2" sch 40. The nuber is hard to read on the only piece I have left ASTM A68(E or F?) A Not sure about the 8 either. Sorry can't upload the pic. But the piece also says steel. The only thing I don't like is the weight. I hit some of it with a sledge before deciding to use it and hardly made a mark. I'm betting my life on it.

I just went out to the garage and laiad a piece on two wood blocks and gave it a hell of a wack with the big sledge. There's a little ding that's it.

Originally posted by dmracing
I just went out to the garage and laiad a piece on two wood blocks and gave it a hell of a wack with the big sledge. There's a little ding that's it.

u fella on the other side of the mountain scare me!:)

Not nuts here. The replys here just got me thinkin about my neck. Flops on the side are common at the races. I have'nt done it yet but it will happen. especially on the short courses when you're mashing it.. Just makin sure.

dont be scared...pipes works fine lots of guys that run the miler have pipe rollcages...some that have doing it for many years...if can run 40-50 mph or whatever speed they get up to on I81(i think thats what they call ) and bounce off or trees other trucks and such and live to tell about,,,it should work just fine