AISI 5145 is a through-hardening, low-chromium alloy steel of intermediate hardenability. It is used in a number of machinery and tool applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-290. Producer or source: Alloy steel mills and foundries.