Rollcage tubing

[AE86ITA]

I keep looking at the 2007 GCR book and it says that the material and size for the rollcage is in 9.4.1.F.3 and I just gave up and decided to ask because i just can't find it.

Need to know the weight breakdown for both mild steel and cromoly

Thanks,

[erlrich]

See page 89.

[AE86ITA]

See page 89.
[/b]

Thanks,

For some strange reason the file at GCR 2007 (http://www.scca.com/_FileLibrary/File/GCR2007.pdf) does not show pages 88-90.

Thanks,

[tom_sprecher]

I could look up the weights in my Ryerson Stock List or you could Google it. Now, I'd have to go find that book or you could do a little typing and some clicking. Depends on who really needs to know. :P

From memory it's 1.5 x .120 or 1.75 x .090 DOM 1020. I think the 1.75 weighs less per foot.

Have fun.

[joeg]

Pipe is for plumbing; tube is for fabrication.

There is no difference in weight between Chrome Moly and Mild Steel if the tubing is the same wall thickness and diameter.

Steel is steel.

In the "olden" days you could run thinner wall chrome moly. Hence the old weight break.

Cheers.

[AE86ITA]

Pipe is for plumbing; tube is for fabrication.

There is no difference in weight between Chrome Moly and Mild Steel if the tubing is the same wall thickness and diameter.

Steel is steel.

In the "olden" days you could run thinner wall chrome moly. Hence the old weight break.

Cheers.
[/b]

Sorry, keep forgetting that I must think in english if I want to be understood.

Joeg, could you inform us then what are the tube different materials and measurements for rollcage fabrication?

Hope I expressed it right this time.

Thanks,

Efrain

[joeg]

Start with the ITCS--10 (a)--Safety--IT cars use the GCR "Showroom Stock cage configuration" rules (not "Touring" rules).

Go to GCR Section 9.4.2. This sends you to GCR 9.4.1 F. 3 for tube dimensions :

Up to 1500 lb. car weight --1.375 x .095 DOM/ Seamless /Alloy;
1501 - 2200 lbs. --1.500 x .095 DOM / Seamless/ Alloy;
2201- 3000 lbs. --Several choices

"Alloy" includes Chrome Moly. Hence no weight break for that material

[AE86ITA]

Start with the ITCS--10 (a)--Safety--IT cars use the GCR "Showroom Stock cage configuration" rules (not "Touring" rules).

Go to GCR Section 9.4.2. This sends you to GCR 9.4.1 F. 3 for tube dimensions :

Up to 1500 lb. car weight --1.375 x .095 DOM/ Seamless /Alloy;
1501 - 2200 lbs. --1.500 x .095 DOM / Seamless/ Alloy;
2201- 3000 lbs. --Several choices

"Alloy" includes Chrome Moly. Hence no weight break for that material
[/b]

Are we limited to just Chrome Moly or there are other Alloy steels that are easy to get within a budget.

Thanks,

[tom_sprecher]

The primary reason to use 4130 is that for a given strength a thinner wall tubing can be used when compared to 1020. As the man said there is no dimensional reduction allowance for 4130 so you would be better off price wise to use mild steel (1020). Certain precautions need to be taken when welding 4130. When using MIG or TIG the joints can become martensitic (brittle). Many Formula car chassis are brazed 4130 for that reason.

[AE86ITA]

The primary reason to use 4130 is that for a given strength a thinner wall tubing can be used when compared to 1020. As the man said there is no dimensional reduction allowance for 4130 so you would be better off price wise to use mild steel (1020). Certain precautions need to be taken when welding 4130. When using MIG or TIG the joints can become martensitic (brittle). Many Formula car chassis are brazed 4130 for that reason.
[/b]

Thanks Tom:

So is it fear to say that mild steel is an Alloy steel? Is there a literature that will support that. Today as I was about to place the order for the tubing the gentleman at the counter told me that mild steel was not an alloy steel.

Thanks again,

[joeg]

Just order DOM (Drawn Over Mandrel) mild steel.

Forget "alloy"

Cheers.

[Speed Raycer]

Certain precautions need to be taken when welding 4130. When using MIG or TIG the joints can become martensitic (brittle). Many Formula car chassis are brazed 4130 for that reason.
[/b]
Which is really odd as the chassis' could easily be heat treated.

As mentioned above ^^^^ just get DOM Mild Steel 1020-1026 and save yourself a couple Benjamins for materials and a lot more Bengies on installation ;)

[ddewhurst]

***Is there a literature that will support that.***

If you had an educational metal book or if you do a Google search you should find the following to be true.

Steel is a crystalline alloy of iron, carbon & several other elements, which hardens when quenched above it's critical temperature.

Alloy steels have been clasiffied by the Socity of American Engineers & by the American Iron & Steel Institute. One of the alloy steels classified is 10?? series steel with another being the 41?? series.

***So is it fear to say that mild steel is an Alloy steel?***

As an example 1020 is .20% of 1% carbon. It is fair to say that 1020 is an alloy steel.

AE86ITA, two suggestions for you. Please as someone earlier suggested call your roll cage material TUBE. Pipe is what we take into the alley & use to beat the $hit out of someone with. :blink:

Second, to make yourself feel more positive about the above information please call SCCA Topeka, KS 1-800-770-2055 x336 ak for Jeremy to confirm the information provided above is correct.

Next item is to talk to the person who will weld your roll cage & ask him/her which steel he/she may do the best weld job with.

Get receipt from the steel vendor that has the word 1020 alloy steel typed on the sheet of paper.

Have Fun ;)
David

[AE86ITA]

Thanks David:
You have been most helpful. I stand corrected and tubing it is and will be. I have just talked to Jeremy and he confirmed your information and guided me in the right direction.

Thanks everyone who pitched in and gave a helping hand. Now is time to buy some tubing........


Muchas gracias,