I've been trying to determine which is stronger, square tubing or Round tubing. I searched the forum but came up with some other ideas but not the answer. Using a Square tubing that's 2"x2" AND .25" thick vs. a Round Tubing that's 2" outside diameter and 1.5" inside Diameter and both are 5' long, as my example. My Force is 4,000 lbs. I calculated the Maximum Stress in a beam with uniform support at the ends, and my Force in the middle of the beam. My numbers are M.S. for Square tubing is 13,713.66 psi and M.S. for Round tubing is 23,325.24 psi. Does this mean that the Square tubing is stronger then the Round tubing? Or am I misunderstanding the definition of Maximum Stress. Also why is it I hear Round tubing is Stronger then Square tubing?