Sources and scope for this page: Industry convention — no single governing standard (conventional usage, definitions vary between sources), covering the definition of tensile strength (uts). No independent source check is recorded for this page: the content rests on the sources listed and on the working shown on the page. How sources, methods and updates are recorded.
Definition
Tensile strength is the peak of the stress-strain curve. It is the most-quoted strength figure and the least useful for design, because a part that reaches it is already permanently deformed and about to fail.
Design against yield, not ultimate. The tensile figure is for comparing materials and for acceptance testing, not for sizing a part that must remain functional.
Common misuse
Designing a part against tensile strength with no margin, which means it will yield in service long before the calculation says it fails.