Tenacity

This article is about the measure of textile strength. For the geologic term, see Tenacity (mineralogy). For the Herbicide, see Mesotrione.

Tenacity is the customary measure of strength of a fiber or yarn. In the U.S. it is usually defined as the ultimate (breaking) strength of the fiber (in gram-force units) divided by the denier.

Because denier is a measure of the linear density, the tenacity works out to be not a measure of force per unit area, but rather a quasi-dimensionless measure analogous to specific strength.