Reinforced Fire Door? With most of the industry going to a “composite” style door (shown on the next page), Fort Knox reinforces the door. A solid plate starts the process, followed by two layers of fire board and another layer of steel. This process gives Fort Knox more steel in the door than that of a “composite” door as well as giving us the added strength that comes from the steel radius on the edge of the door. The radius or bends in the door add strength but only if it is supported from the inside of the door with extra steel. More steel plus the radius edges make the best door in the industry. Feel the difference by opening a Fort Knox door and then a competitor’s door. You will be able to feel the difference.