Some companies that sell commercial exterior steel doors are Home Depot and Grainger. As of September 2015, Home Depot carries steel doors by L.I.F Industries and Architectural Elements, while Grainger carries steel doors by Ceco, Ceco-Envoy and Curries.
One of the best selling commercial exterior steel doors at Home Depot is the gray right-hand flush security steel prehung commercial door by L.I.F Industries. This heavy-duty steel door measures 36 inches by 80 inches and is ready to install. It can prevent the spread of both fire and smoke for up to 90 minutes. This door is suitable for both interior and exterior use.