I'm not an engineer, but it's my understanding that the yield strength is
a function of the material/alloy and is independent of the dimensions. So
4130 has the same yield strength regardless of it's dimensions.
You need to calculate the section modulus, which for round tubing is:
Pi*(D^4 - d^4)/32D
where D is the outer diameter and d is the inner diameter.
You then calculate the maximum bending moment, which I think is what you
are really after, by multiplying the section modulus by the yield strength.
This answer is the maximum force, measured in inch-lbs, that the material
A quick check on the calculator shows that for 1 inch OD tubing, the
0.120 wall material (4130) has about 59% of the strength of the 0.25 wall
material. For 2 inch OD tubing, the 0.120 wall tubing is only 53% as
strong as the 0.25 wall tubing. So you see that to really answer your
question we have to know the specific diameters involved.
I hope some of the engineers can set me straight if I have this wrong.
73, Arliss W7XU
"Mike Nash, ND6A" wrote:
> I have a quick question regarding strenth of this stuff
> In using the Marc program I see that 4130 has a yield strength of 115000
> psi for .250 wall thickness.
> What is the strength for .120 wall thickness?
> Is it exactly half?
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