[TowerTalk] Mast Material

[jimlux]

   Yet the section modulus of the 2.875"  x  .25"  wall   tube is  a 
helluva  lot bigger than my 2" x .375" mast.
>

It's that radius to the fourth power thing...  For a given mass of 
metal, the strongest column will be with the largest diameter and the 
thinnest wall.

The caveat is that a wall that is too thin will dent, and then all the 
assumptions about strength go out the window, because you've no longer 
got a nice uniform beam in bending.

(practical example.. stand on one foot on top of an empty soda/beer can. 
  Then tap the side of the can. )