"Mark" wrote in message
...


todd wrote:


Since you're assuming that the round post has the center of the tree as
it's center, I'll assume that the square post is the same. Therefore,
the
square post contains all of the material of the round post, plus the
material in the square corners. Unless you can explain how added
material
in the corners weakens the post, consider your postulate rebutted.



Because where the grain exits/ enters the post it creates uneven stress.

I suppose that sounds good, but I don't think in practice it's really going
to have a very large effect at all, if any. In the worst case, if we
assumed that the shear strength between growth rings was very low, you might
be able to argue that it really wouldn't help, but I don't see how it would
hurt. This isn't like machining a notch into the additional area that would
create a stress concentration, which could actually produce an overall
weaker member (heh, heh....he said "member").

todd