HY-100 is a low-carbon, hardenable alloy steel for ultra-service applications requiring excellent notch toughness and high strength. It can be welded to provide tough weldments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-255. Producer or source: United States Steel Corporation.