Advise for the nu-bee!

[Paul A.]

A nu-bee here! I need some advice. How much differance in strangth is there in 1'' .095 steel tube and 1'' .120 aluminun tube?

[Hotfoot]

Bending, pulling, pushing...???

[James D. Clark]

Welcome aboard. It depends on what kind of strength you want to compare. I assume it's tensile strength-the amount of force that it would take to pull the tubing into two pieces. Then that would depend on what kind of steel and what kind of aluminum. For example 6061-0 aluminum is about 2-1/2 weaker than 6061-T6 in tensile strength. The weakest carbon steel is still stronger than any aluminum of equal cross section. Your example of .095 steel and .125 aluminum, the steel is much stronger than the softest aluminum and still slightly stronger than the hardest aluminum for those sizes. High strength steels are even stronger. This is a rough comparison based on some strength charts and hasty calculations.

[david_r]

Paul,
A 10' length of that steel tubing, simply supported with a 100 lb load at the center would deflect 2.5 inches If it was the thicker aluminum, it would deflect 6.5 inches.
This is assuming the steel has a modulus of elasticity of 30 x 10^6 and the aluminum 10 x 10^6
Now if you went to 1x2 x .065 aluminum, it would deflect 1.2 inches. If you went with 1.5 x 0.75 x 0.125, it would deflect 1.6 inches, if it was mounted long side vertical.

That's what my calculators say, anyway.