Abstract ATI 303 is a free-machining stainless steel specifically designed to exhibit improved machinability. It is the free-machining modification of the basic 18% chromium-8% nickel stainless steel. Sulfur is added to produce the free-machining characteristics. The good mechanical and corrosion-resistant properties of the lower-sulfur grade are retained to the extent possible. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1361. Producer or source: ATI.