It is 1 1/4" square tubing with 1/8" walls. As for the eyebolts, they are galvanized. They are rated for 1200 #'s. I drilled a hole through the top rail all the way through both sides. I put the eyebolts through, and placed a flat washer followed by a lock washer. I then put a standard nut tightened all the way down. I followed that up with a lock nut tightened snug against the regular nut. After this was done, we placed the top rail on the vertical posts, and welded them on. It should have no problems staying in place.
That's first class stuff there.
