[TowerTalk] PIPE ANCHORS

[Jim Lux]

On 10/30/11 10:39 AM, Grant Saviers wrote:
> A couple more comments, some not covered before:  (all comments w/o
> engineering calcs - YMMV)
>
> 1.  Square tube is stiffer/stronger than round pipe or wide flange beams
> (I-beams) of same #/ft..

Hmm. I'm not sure this is true.  Bending strength goes as the radius to 
the 4th power, and for a given perimeter, a circle has the section 
moment.  (sort of like a circle has the most included area for a given 
perimeter).

Cross sections with right angles are easier to use in construction, 
especially for bolted connections, and a I beam typically has more metal 
farther from the center than a square tube (which is why they use that 
shape).

However, in "practical sizes commonly sold" it might be true that 
squares are stronger than circles.