Linked from
The 11 pages that link to Tensile testing, each with the reason it gives.
Yield strengthRelated: It commonly produces the stress–strain data used to determine yield strength.
DuctilityRelated: Standard ductility measures come from a specimen pulled to fracture.
Elastic modulusRelated: The stress–strain curve commonly supplies Young's modulus.
Stress–strain curveRelated: It produces the data used to construct a tensile stress–strain curve.