Which is stronger? Tube or channel?

Nov 07, 2006 4 Replies

I'm making some light duty lifting forks, under 500lbs.



And I plan to make them out of 3/16 thick, 1 inch by 4 inch tubing.



Now I am wondering if 4 inch channel might be just as good or good enough etc.



The lengths will be fastened on the end and then 30 inches in from end, and they will extend 36 inches, max 500lbs.



Thanks.



It may be good enough, but it won't be as good. Tube is stronger. Rectangular tube is stronger than round tube in bending; round tube is stronger in torsion (twisting). Both are stronger than channel.

-- Ed Humtress

stone:

My material listing does not contain 1" x 4" x 3/16" hollow structural section tube (HSS).

Perhaps it is 2" x 4" x 3/16" tube?

Further, I assume you are loading it in the weak direction (ie. the 4" dimension horizontal).

If it is 2 x 4 tube it is quite a bit stronger than channel. You can look this up yourself by comparing the section modulus (usually denoted as "Z" or "S" in engineering tables) of the beams you are interested in. Just make sure you use the figure for the correct neutral axis.

Example: 2 x 4 x 3/16 has a section modulus of 1.28 cubic inches when bent "the weak way". A standard channel C4 x 7.25 (1.72" flange width) bent in the weak direction has a section modulus of .34 cubic inches. Therefore the 2 x 4 tube is almost 4 times stronger than the channel if both are of the same quality steel with similar yield strengths.

Trust this helps.

Wolfgang

st> I'm making some light duty lifting forks, under 500lbs.

Wow, 4 times stronger. That's amazing.

I planned on using tubing, but then I started wondering about channel.

(I will use 2 x 4, I didn't know the other wasn't available)

And I was intending to use the tubing the weak direction.

Thanks very, very, much!

PS. How much stronger is the tubing in the strong direction? Versus the weak direction.

snipped-for-privacy@hotmail.com wrote:

stone,

In the strong direction the 2" x 4" x 3/16" HSS has a section modulus of 1.91 cubic inches.

It is therefore almost 50% stronger when used in this direction.

Wolfgang

P.S.: My reference tome for information of this type is entitled HANDBOOK OF STEEL CONSTRUCTION published by the Canadian Institute of Steel Construction. There are similar publications in the US. Most worthwhile to own even an older edition of this work. wfh.

st> Wow, 4 times stronger. That's amazing.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required