Tensile strength is a measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks.
The tensile strength of a material is the maximum amount of tensile stress that it can take before failure, for example breaking.
There are three typical definitions of tensile strength:
A distinction is often made between the "nominal" stress σ 
("engineer voltage") and the "true" voltage σ 
.
The (nominal) stress values (tensile strength, yield strength) read from the stress-strain diagram do not correspond to the true stress in the material. This is due to the fact that when calculating the nominal stress, the tensile force is related to the initial cross-section.
In the tensile specimen, however, the true cross-section is smaller than the initial cross-section due to transverse contraction or necking; this deformation (elongation and necking) is visible and measurable after the test in the case of elastic-plastic deformation, i.e. specimens made of ductile materials. The true tensile strength is therefore not equal to the nominal stress in the specimen at the moment of fracture, but is higher.
However, since real loads are mostly applied forces that have an absolute magnitude and are not cross-sectional area related, the nominal tensile strength is usually the governing factor when dimensioning components.
For dimensioning in engineering, the yield strength is used instead. The tensile strength plays a role, for example, in manufacturing during forming or machining. Brittle materials, on the other hand, are dimensioned according to tensile strength, but with these materials there is also no relevant necking and therefore no difference between nominal and true stress. In short: technically, a component has long since failed when the tensile strength is reached, with or without necking.
The maximum true stress occurs in the necking area of the specimen. Here, the deformation and, at best, the strain hardening increases until fracture occurs.
In the instrumented tensile test, the specimen cross-section is measured continuously and the force is related to the true cross-section. Specimens examined in this way show a continuous increase in true stress until failure (blue curve in Fig.). However, the value determined in this way is only of theoretical significance.
Tensile strength has often been used in the past to characterize materials. An example of this is the designation of structural steels. Steel 52 (St52, today S355), for example, was designated according to its tensile strength of 52 kp/mm² (510 N/mm²).
Due to the harmonization of European and international standards, many steels are now designated according to yield strength, which is a better characteristic value for the load-bearing capacity of a material from a design point of view.
| Material | Tensile strength inN/mm² |
| 7–70 | |
| 10 to 15 | |
| 15 | |
| 45 | |
| 45 to 64 | |
| 150 till 350 | |
| Aluminum alloys | mostly 200 to 450; rarely up to 640 |
| Cast iron with lamellar graphite | 100 till 350 |
| human hair | 200 |
| Titanium alloys | 290 till 1200 |
| Structural steel | 310 to 690 |
| Alloy steel | 1100 till 1300 |
| Dyneema | 3000 |
| up to 63.000 |
A: Tensile strength is the amount of force needed to pull an object like a rope, wire, or a structural beam until it breaks.
A: The maximum amount of stress that a material can endure before failure is known as its tensile strength.
A: Yes, objects like rope, wire, and structural beams are tested for tensile strength.
A: There are three typical definitions of tensile strength.
A: The first definition of tensile strength is that it is the force required to break a material when it is pulled.
A: The second definition of tensile strength is that it is the maximum amount of stress that can be sustained by a material before its failure.
A: The third definition of tensile strength is that it is the measure of a material's ability to resist breaking under tension.
