Frame tubing

[JHen]

I've got a project I'm in the planning stage of. I have an old 93 Cavalier that is a derelict now. I plan to cannibalize the parts from it and make a two seat, off road, street legal buggy. My question right now is tube. I want to use 4130 DOM tube, but I'm not sure on the size. I was thinking something like 1.5" diameter and .095 wall thickness for the main structural bits like roll cage and what not. I'm going to try to keep the wheel base so it will fit inside of a 4' x 8' truck bed to give you an idea on total size. Not sure if that is doable or not yet.

So, is 1.5" x .095" 4130 DOM too much, not enough, or just right for such a project.

 

[TorqueRanger]

All roll bar and cages are .120 min Dom (drawn over mandrel) tubing.. That size tubing is a good size to stick with ..

 

[JHen]

Is that mild steel or 4130 though? 4130 is a lot stronger than mild steel tubing so you can have a thinner wall and have it just as strong (and in turn a lighter frame).

 

[Rickracer]

4130 absolutely must be TIG welded, .120 wall DOM is a far better choice. Pick your tubing size accordingly, 1.5" is almost a bit much for a frame that size, IMHO, but if you did the main frame out of that, and downsized the rest to, say, 1", it would work well.

 

[devino246]

4130 absolutely must be TIG welded, .120 wall DOM is a far better choice. Pick your tubing size accordingly, 1.5" is almost a bit much for a frame that size, IMHO, but if you did the main frame out of that, and downsized the rest to, say, 1", it would work well.

Plus heat treated. And theres no reason to use DOM, welded seam is fine for a kart frame

 

[JHen]

DOM does have a welded seem, it just then gets drawn over a mandrel that makes it more uniform and it also takes out the visual of the seam.

Also, this is a really big 'kart' lol. A 2.2L engine.

 

[Rickracer]

1.5" is probably just about right for that then. It doesn't all have to be that size though. You can use smaller material for triangulation.

 

[Doc Sprocket]

DOM does have a welded seem, it just then gets drawn over a mandrel that makes it more uniform and it also takes out the visual of the seam.

It certainly does. But I believe the intended point was that drawing that welded seam tubing over said mandrel adds a fair bit to the cost, and really isn't altogether that necessary.

For clarity, (and I think this was PART of the point), plain welded seam tube is generally referred to as "welded seam" (aka ERW), and although the DOM starts out as welded seam, it is never referred to as welded seam or ERW.