(ca. 1864) n. The maximum nominal stress sustained by a test specimen being pulled from both ends, at a specified temperature and at a specified rate of stretching. When the maximum nominal stress occurs at the yield point it shall be designated tensile strength at yield. When it occurs at break, it shall be designated tensile strength at break. The ASTM test for plastics is D 638 (metric, D 638M). The SI unit or tensile strength is the pascal (N/m²), but trade publications in the USA are still clinging to the pound (force) per square inch (psi). The strengths of commercial plastics that are neither plasticized nor fiber-reinforced range from about 14 to 140 MPa (2–20 kpsi).

See strength, tensile.