Allegheny Technologies Inc. (ATI) has announced that one of its proprietary alloys is being used for the largest stainless roof in the world. The roof is for the New Doha International Airport in Qatar. ATI Allegheny Ludlum, an ATI company, supplied 3.5 million pounds of its proprietary AL 2003™ lean duplex stainless sheet to Contrarian Metal Resources, Allison Park, Pennsylvania, USA, for this project. The airport specified that Contrarian apply its proprietary architectural matte finish, InvariMatte™, on the AL 2003 lean duplex stainless alloy for added aesthetic value and for glare resistance. At almost two million square feet, the airport’s roof will have the largest stainless roof in the world when completed. Major alloying elements of AL 2003 alloy include: chromium 21%, nickel 3%, and molybdenum 1.5%. AL 2003 alloy has full ASTM coverage and is ASME qualified under Code Case 2503. Additionally, AL 2003 alloy is approved by the Norwegian petroleum industry standard NORSOK M-650, and is certified as an acceptable material for use in drinking water systems by NSF/ANSI Standard 61.