Oh boy, here is goes again. The HREW vs. DOM vs Pipe goes on and on.
General Consensus:
HREW: Generally fine for cages inside a full size rig doing what most of us do. Typically only needs to endure one hard roll since it's going to kill the truck anyway, and as long as the occupants are kept safe, who cares. Certainly strong enough to handle a flop or soft roll without damage assuming even a decent design. But yes, the seam needs to go inside the bend. My truggy is done completely with HREW and has sustained multiple flops without issue. I don't recall ever seeing a single instance of someone being injured or killed and the HREW cage was blamed.
DOM: Better and more likely to survive flops/rolls intact. Tougher (more dent resistant) and much better when the cage (or buggy) is expected to survive multiple rolls and remain in good, usable shape. Often used only on impact surfaces of buggies with HREW everywhere else. Yes, racing sanctioning bodies often do specify DOM or better among other things, often including design as well. But those guys are running 100+mph and are *expecting* catastrophic crashes. Big difference between that and the unexpected trail flops or even highway rolls. These trucks have remarkable survivability even in highway rolls, so the cage is only backup if you don't have a full convert. Do you need to use DOM? Maybe, but probably not. Only you can figure out what you really need (or just simply want for "piece of mind"). Going by what "sanctioning bodies" for unrelated applications do really makes very little sense. Are you also going to follow the rest of the rules too? Or is this just a convenient pick and choose? Are you going to use your vehicle in the same way as the sports involved? If not, then why use said sanctioning body rules as a justification for material selection? If your only looking for survivability in a crash that destroys your truck, then DOM is generally not needed, though it might make a difference if the design is poor or otherwise compromised, but there is no substitute for a good design.
ChroMo: Way over-kill and too much trouble unless you REALLY NEED minimal weight.
Pipe: Many feel it can be ok as long as you get graded pipe with the proper ratings, some random cheap import stuff from "Wholesale Plumbing Supply" or something. A number of heavily beat on dedicated rock buggies have been built with pipe and no deaths or failures reported yet. However, the end result tends to be heavier due to the pipe dimensioning system and the need often go bigger/thicker to make up for deficiencies in pipe relative to comparable tube. But there is always the "expert" who must inform everyone that "pipe is for poop" and if you use it for a cage, YOUR GONNA DIEEEE!!
Not something I would use, but that's a personal choice based on my opinions and how I think it fits with what I want to do or want, just like DOM vs. HREW.
For more of the inevitable details, anyone interested can search and find plenty.
) so I think with a properly built HREW cage can handle a roll and as many flops as you got. Nothing wrong with DOM in fact have it in other areas of my truck but just think that HREW will do the job just fine and why not save a little money. As far as pipe goes, I have a buddy that used pipe to build his rock slides and seem to be plenty strong, there is even people that use pipe for cages and have no issues, but for me....no way, sch 40 is to inconsistent in wall thickness for me to risk that. I don't roll my eyes at people who use pipe. I'm just not gonna use it is all.
