Aluminium tube bending and resistance

Wait a bit, I didn't notice there were other posts. Let me read them all first.

HM

Reply to
H. Martins
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That's OK, I had the wrong message sort.

HM.

Reply to
H. Martins

Yes.

Ned Simmons

Reply to
Ned Simmons

I was a bit astonished too. My books says something of 0.675...0.715E5 for Al. And I don't have a table showing something like 6061. Don't know.

Yea, the abbrevs are the German ones. And I _really_ don't know how you translate them. :-)) S for section modulus. That sounds very right to me.

Thanks for checking!

Nick

Reply to
Nick Müller

Yes, and then I saw that I forgot to note that it is for Al, and postet the clarification some minutes later.

Exactly.

No, it is a constant, depending from the material. For steel, it is

2.1E5.

OK :-)

What square of the length? I have never written that. N / mm^2 is the unit, not a formula. For every symbol I used, I gave the units. If you do the math just with the units, you can check the result a bit. N is a unit (Newton, force) and I described it to. I didn't use N as a symbol. It's also quite confusing to use the units in a formula. So I didn't, except for the result.

I always use the same pattern: Write the formula and then, with the same sequence put in the numbers. No shortcuts, no numbers that aren't derived from a formula. Your last statement is wrong.

Nick

Reply to
Nick Müller

OK. I messed it al. All is clear now.

Let me follow through the other matters, I will come back.

Thank you Nick. Henrique

Reply to
H. Martins

If you're an Iraqi, and are ordering it in quantities in the tens of thousands, then the price is about $15 for an 81mm tube 900mm long, with

3.1mm wall thickness and 0.1mm wall thickness tolerance, and in the -T6 heat treatment state.

That includes the special fee for busting sanctions on nuclear-related materials.

Reply to
Norman Yarvin

About $3.60/lb. - pretty good price. Almost exactly Yarde's price for drops of 7075 solid rounds.

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There must be lots of competition for that business.

Ned Simmons

Reply to
Ned Simmons

They shopped it around for quotes. :-)

These were, of course, the infamous aluminum tubes whose interception on their way to Iraq was used as part of the justification for war. The supposedly extraordinarily-tight tolerances were:

Outer diameter: 81.0 +0 / -0.1 mm Inner diameter: 74.4 +0.1 / -0 mm

Somehow those numbers never seemed to make it into press reports -- not even after the war. I had to dig them out of the Duelfer report (where they're in volume 2, second section, in page 27 of that section, which is page 164 of the pdf file).

Reply to
Norman Yarvin

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