Tensile strength

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:

• Yield strength - The stress a material can withstand without permanent deformation. This is not a sharply defined point. Yield strength is the stress which will cause a permanent deformation of 0.2% of the original dimension.

• Ultimate strength - The maximum stress a material can withstand.

• Breaking strength - The stress coordinate on the stress-strain curve at the point of rupture.

Some typical tensile strengths of some materials:

• Note: Multiwalled carbon nanotubes have the highest tensile strength of any material yet measured, with labs producing them at a tensile strength of 63 GPa, still well below their theoretical limit of 300 GPa. However, as of 2004, no macroscopic object constructed of carbon nanotubes has had a tensile strength remotely approaching this figure, or substantially exceeding that of high-strength materials like Kevlar.

• Note: many of the values depend on manufacturing process and purity/composition.

(Source: A.M. Howatson, P.G. Lund and J.D. Todd, "Engineering Tables and Data" p41)

• Tension (mechanics)
• Tensile stress
• Deformation

• January 2003 sci.physics thread on water tensile strength and trees
• Theory re the discrepancy in static vs dynamic measurements of water's tensile strength