Rectangular Square Tubing

[dskarupa]

Does anyone know where I can find specs on Rectangular Square steel Tubing? I want to use 6" x 4" x 1/8" wall tubing with a span of 32' between post with a load of 50 lbs/ft. I want to know if this will deflect and how much? Can someone help me with this or know where I can get the information?

 

[brad]

Can't you just calculate MOI and use simply supported beam assumptions with a constant pressure load? (or am I missing something)

Brad

 

[profengmen]

Rectangular Square?

 

[dskarupa]

How would I calculate MOI on a Rectangular Square steel Tubing? This is to be used for an indexing line where the load is distributed across 32 ft, both ends are fix.

 

[brad]

If you know the cross-sectional geometry, you can fairly easily calculate moments of inertia.
Brad

 

[profengmen]

I think you might want to consult with an engineer... Get the advice of a Structural PE.

What you are asking is painfully easy, and by asking it suggests that you are out of your area of expertise.

The structural properties of square tubing or rectangular tubing (there is no such thing as "Rectangular Square") can be found in the Manufacturer's catalog. For example, Central Steel or Century Steel catalog. The specifications are called out in ASTM or MIL or ASME references that you should know how to look up.

Calculating the deflection is as easy as looking up the formula for deflection, which should be in the reference book that should be in your bookshelf.

 

[CorBlimeyLimey]

I want to know if this will deflect

Yes ... it will deflect under it's own weight.

Sorry, but if you dont know how to do this ... you shouldn't be ... unless you are just trying to learn. If so, I suggest you get a book, take a course or get advice from someone who is structurally savvy. There is also loads of information on the web.

http://www.engineersedge.com/beam_defl_even.htm

from (the City of) Barrie, Ontario.

I tried sniffing Coke once, but the ice cubes got stuck in my nose

 

[JStephen]

You can approximate the moment of inertia fairly easily by deducting the MOI of the hole from the MOI of the outside. This doesn't allow for the radiused corners, but gets reasonably close.

There is a design manual out for hollow steel tubing; I'm not sure who publishes it. Steel tubing is also included in AISC-ASD, but it only goes down to 3/16" wall thickness in 6"x4".

 

[JStephen]

The hollow tubing manual I was thinking about was published by AISC, also.

Be aware that the strength of a thin-walled tube may be based on local buckling, either due to bending stresses or at the supports.