DOM vs HREW Tubing

[Packard John]

I am fabricating a 3 ft. cross member for an upper shock mount, on the rear of a 4,200 lb. body on frame car with leaf springs. The shocks will have helper springs. I will need to use 3" tube to fit the mounts. I can get HREW and DOM tube, the thickest HREW is 0.120" The DOM comes in may sizes 0.120" to 0.500" HREW is cheaper. Is HREW acceptable for a crossmember or should I use DOM? Also 0.120" is thick enough?

[raustinss]

3 inch tube ?????? you absolutely dont need anything even close to that size

[Packard John]

The size is more for conveince than anything else based on pre-made mounts and attaching to frame. So I guess at that size 0.120" HREW would be of no concern?

[dontlifttoshift]

It depends on the mounts. If they are cantilevered out 8 inches and only welded to 25% of the tube diameter, I don't feel great about that.

Pictures are worth a thousand words, can you show us what you are doing and maybe a pic of the mounts that you already have?

[Packard John]

Donny
Yes they only engage about 25% of the tube but only cantilever out a few inches.213850

[cornfedbill]

In this application, either material will suffice. A 3" tube seems to be more than you need, especially if it is 0.120" wall. Either way, you won't need to worry about it failing as long as the welds are of good quality.

[Packard John]

Thanks.