The bins are made of heavy gauge corrugated galvanized steel ensuring its strength and durability. Built without interior or exterior stiffeners and made of heavy gauge ultra-flat 4" corrugated galvanized steel, Wide-Corr® Farm Series grain bins offer superior strength and unbeatable versatility, and are engineered for exceptional clean out. And as with all AGI Westeel products, computer-assisted machining ensures precision cuts and tighter seals, making for incredibly easy assembly. Plus, AGI Westeel unstiffened bins can also be used as a hopper bin when paired with a hopper cone.