Premierâ„¢ bi-fold hangar doors are made of 6061-T6 aluminum that is lighter, yet stronger than steel framed alternatives. They are custom built to match your exact specifications, are easy to install, and have one of the lowest life cycle costs in the industry. Regardless of the environment, the raw mill finish provides a clean, crisp look and higher aesthetic value than steel products. There is no rusting or chipping paint, and you can clad your door with any covering to achieve the look you desire. You get the size and strength you need, with the style you want.