AISI 81B45 is a nickel-chromium-molybdenum alloy steel to which boron has been added to increase its hardenability. It has intermediate hardenability for medium-duty applications. Its many uses include axles, gears and machinery components. 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: SA-337. Producer or source: Alloy steel mills and foundries.