Force per unit of original cross-sectional area (stress), loaded in tension, at which mechanical failure occurs. Ultimate tensile strength (UTS) is measured at rupture, while yield tensile strength is measured at the onset of irreversible plastic deformation.
Relevant ASTM testing standards include C1273 and C1366 for ceramics (at ambient and elevated temperatures, respectively), D412 for elastomers, D638 for plastics, D1623 for rigid polymeric foams, D3039 for polymeric-matrix composites, D3552 for metal-matrix composites, and E8 for metals.
ISO tests include 37 for elastomers, 527 for plastics, 1926 for rigid polymeric foams, and 6892 for metals. ISO testing standards for the tensile properties of ceramics are heavily fragmented.