UNS No. H51321 is a medium-hardenability, through-hardening steel of low (0.75-1.00%) chromium content. It is recommended for uses where moderate strength and toughness are satisfactory. It may be used in the unhardened condition or after quenching in water or oil followed by tempering to the desired strength level. 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-416. Producer or source: Alloy steel mills and foundries.