I wouldn't substitute tube for the angle in a trailer application. Reason is
that short of hot dip galvanizing, you can't rust proof the inside of the
tube. Water will get inside and eventually the frame will rust from the
inside out leading to failure. Do yourself a favor and follow the original
plans.
Just my .02 YMMV.
Paul

"Edward A. Falk" wrote in message
...
Hi all; about to start building a trailer. The trailer plans I
bought from trailerplans.com call for 2"x3"x1/4" angle iron. I
want to use steel tube instead. Can anybody give me an idea of what
size steel tube would have the same strength? Is there somewhere
this can be looked up?

--
-Ed Falk,
http://thespamdiaries.blogspot.com/