Strength of any material is the MAXIMUM stress it can take without failing.
Strength refers to the ability of a structure to resist loads without failure because of excessive stress or deformation.
Typical points of interest when testing a material include: <strong>ultimate tensile strength (UTS) or peak stress; offset yield strength (OYS) which represents a point just beyond the onset of permanent deformation; and the rupture (R) or fracture point where the specimen separates into pieces.
Strength of Materials Lectures Notes