ISO 19819:2004 specifies the method of tensile testing of metallic materials in liquid helium (boiling point at - 269 C or 4,2 K) and defines the mechanical properties that can be determined.
ISO 19819:2004 may also apply to tensile testing at cryogenic temperatures (less than - 196 C or 77 K), which requires special apparatus, smaller specimens, and concern for serrated yielding, adiabatic heating and strain-rate effects.