Who does roll cages?

[Pushit2.0]

No seam welded pipe is legal, but most of the pre bent 6 point roll bar kits, good for a 9.99@135 is seam welded mild steel.

Then if you look at the 8 point roll cage, good to a 8.50@150 certified with a window net this needs to be 1 5/8" .120 wall mild steel DOM tubing, or 1 5/8" .083 wall chrome moly DOM. The "D" bars in a unibody car need to go to some type of frame rail, so a 2x3 mild steel frame rail needs to be added between the hoop up rights as a frame rail. The D bar takes a lot of the load in a roll over, so the tin can floor pan is not designed to take this load. And if you put a 6"x6" plate fully welded it will push down about 3" before ripping threw the floor, so when I do a hoop for a 8 point cage I weld in 3 plates in a major structural spot on the unibody, then with the frame rail across it gives you the best chance of it holding up in a roll over.

~John