Tensile strength (TS) is a measure used to describe the maximum pulling pressure a material can manage, before the cross-section begins to notably contract. The real term for tensile strength is ultimate tensile strength (UTS), but this is commonly shortened to tensile strength.
In order to determine the UTS of nylon webbing, for example, the amount of stress the webbing can withstand is measured by using machines to pull with increasing pressure. This is not necessarily based on the material’s size.
Other measures, however, do take size into account. This is generally measured as force per unit area. It is a common practice to use the unit of pounds-force per square inch (psi) or kilo-pounds per square inch, for a psi in multiples of 1000.
Some factors that can influence UTS testing are flaws or defects in the material and temperature in the testing area. Thus, it is important for testing labs to examine the material to be tested, thoroughly, for any defects or weak spots and monitor the temperature for the test.
Usually, when the test reaches close to the maximum tensile strength of the material, it is measured as a curve, called the stress-strain curve. The stress-strain curve will reach a peak of pressure withstood, before the material begins to show visible strain against the pressure. This peak is measured and listed as the ultimate tensile strength.