Crossmember material

[jaybee]

"Because it was laying around" is a poor reason to choose any particular material or part for use, but...

I'm in possession of some used semi-trailer floor crossmembers, cut out due to damage on the ends so they're at or nearly 102" long. They are fabricated I beams made from material that's roughly the thickness of an automobile frame, 2" top and bottom plates, 4" tall.

Can this material be used to construct crossmembers and X-members sufficient to beef up a chassis for street performance? They're plenty strong enough to carry loaded forklifts, but I wonder how much torsional rigidity is lost, and if proper design can help compensate.

I know it'll work for my other potential use, which is to set it across the base webs of multiple roof trusses in the garage to spread lifting loads across the width of the ceiling. Kind of like a poor man's overhead crane.

[jaybee]

I have the material home now and it's 2"x4"x.125. Any opinions?

[PhillipM]

Pictures would be cool.

[jaybee]

Pictures would be cool.

I'll try to get some pics. Think I got a good suggestion on how to use it, too. Box one side, it effectively becomes a 1"x4"x.125" rectangular tube with flanges on one side. I think that would make it easier to cut holes diagonally through for things like exhaust, when it's running on a diagonal, too. Run a tube through the web as reinforcement, then make a boxing plate to match. How much stiffer would it be to box both sides, turning it into two tubes side by side sharing one wall?

[parsonsj]

2x4x.120 is what companies like Art Morrison use in their custom frames. It ought to be plenty strong for what you want to do.

jp