The steel part that slides into the aluminum channel gets an angled notch that the end of the bolt sets onto, this means when you tighten the screw, the outer wing panel is pulled tighter to the center section, Believe me, its plenty strong. I mounted it to ply wing webbing. I have full confidence in this product. I researched different methods of attaching wing panels and I felt this was the best and by far the easiest to align and install.
Denny