CREW 1.75" x .120wall tubing, Cage?

I am looking to see if anyone is running this tubing in their race car for their cage. From what I've seen NHRA just says 'mild steel' or chrome moly, I would like to make sure that this stuff is at least under the umbrella of 'mild steel tubing'. DOM comes to mind before CREW as far as I understand...but is CREW accepted and commonly used?

Thanks!

I thought the main issue is if the wall thickness goes to .119", where DOM is more precise.

If you are installing a CAGE and not a BAR, why not go with 1 5/8" tubing?

Jeff

Isn't [ crew ] just black iron pipe? Been used back in the day before mild steel tubing and c/m to build roll bars, can't see a benefit now as the price isn't any lower.

Cold Rolled Electric Weld (CREW) tubing is considered mild steel as is DOM, but it is not the same. The welded seam tubing is not very accurate as far as tolerances are concerned. I have seen .120 wall stuff as thin as .113 or .114. This is the reason places who use this tubing go to .134 wall. That will sometimes run to .128 to .129 thick, still legal for cages and bars. It is also heavy.
DOM is Drawn Over Mandrel and is much more accurate. You can use .120 wall material and still satisfy the .118 minimum thickness requirement. Also, the DOM I have seen has all been 1020 steel where the welded stuff has all been 1010. This means the DOM has a higher carbon content which makes the steel harder. This makes for a stiffer cage assembly. I can tell the difference running a drill bit through it.
Both of these are considered mild steel, but the DOM is higher quality material and as a result is more expensive than CREW or ERW. When you talk to someone about mild steel tubing, make sure you know if it is welded seam or DOM, which is seamless. Personally, I wouldn't use welded seam tubing for anything on a race car.

Actually DOM tubing does have a welded seem similar to HREW or CREW. However, it when it is "cold drawn" to size the welded seem virtually disappears. DOM is far more consistant and definatly a superior tube.