USS AR300 and USS AR350 are economical quenched-and-tempered carbon steels that may be used for applications requiring good resistance to sliding abrasion and impact abrasion. They comprise two grades of steel with about the same nominal composition, differing in hardness and strength largely because of different tempering temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CS-65. Producer or source: United States Steel Corporation.