Floor: 2"x3" 11 ga tubular steel, 16" o.c.
Walls: 1"x1-1/2" 16awg tubular steel, 16" o.c. where possible
Around slide-outs, the box corners & top hat: 1"x3" tubular steel 16 ga.
Bins: Angle iron, 1"x1-1/2" 16 ga. Enclosed with Galvanized steel 20 ga.
The interior steel frame is wire welded...