Outer Limits 4x4 Board

quick poll about choice of roll cage and bar work material. i can get schedule 40 seamless pipe and am contemplating it over welded tube. from my understanding, this stuff is made by spinning hot metal until a void is created in the middle. then it is drawn over mandrel to the correct size. it's not rolled and welded like other pipe and some tube. pretty strong stuff and is used for high pressure lines. i'm considering 40NB which is 48.26mm OD, 3.68mm thickness and $17.42/m; and 50NB which is 60.33mm, 3.91mm and $18.15/m respectively. after trawling pirate, i'm confident this will hold up to much abuse. what are your thoughts? because i'm keeping competition in mind for the future, is this stuff gonna be acceptable or is DOM the go?

so far people have voted seamless - probably because dom costs so much. so can i get into comps with seamless pipe?

Nam,
check the regs for roll cages.
look at what they use in cams registered cars.

Sooner or later these regs will be adopted so may be worth looking at.
Michael.

CAMS do not specify seamless tube. ERW is all they require.