The greatest longitudinal stress a substance can bear without tearing asunder, -- usually expressed with reference to a unit area of the cross section of the substance, as the number of pounds per square inch, or kilograms per square centimeter, necessary to produce rupture.
The relative strength of a thread, calculated by dividing the tensile strength by the thickness of the thread.
A term relating to the strength per size of a thread and is generally measured in grams per denier. The following fibers are ranked according to their tenacity from strongest to weakest: Kevlar® Nylon, Polyester, Nomex®, Lyocell®, Rayon, CS Cotton, CP Cotton. Threads made from continuous filament fibers are stronger and have a higher tenacity than threads made from staple fibers.