 Tensile strength

The ultimate tensile strength in an ordinary tension test is the maximum applied tensile force divided by the specimen's original cross-sectional area:It is the peak engineering stress, not necessarily the stress at final fracture and not the same as yield strength. A specimen with $A_0=10{\mathrm{mm}}^2$ and peak load $5\mathrm{kN}$ has tensile strength $500\mathrm{MPa}$. Necking reduces the current area, so true stress using that area can behave differently after the engineering-stress peak. Temperature, loading rate and specimen preparation belong to the test conditions.^[ref]