Alloy Steel S515 - widely used in the Aerospace industry

BS 2S 515 or more commonly referred to as S515 is a British Standard Aerospace Series, high strength alloyed steel available in sheet and strip form.  S515 has a tensile range 460-600 MPa where its sibling S514 has a typical tensile range 770-1000 MPa when supplied in its hardened and tempered condition.  Where S514 is supplied in the softened condition, it has a hardness only mechanical requirement which is the same as S515, and is therefore often duel released to both standards; BS S515/ S514 (softened condition).