Glossary | Yield Strength
The Yield Strength is defined as the stress that will induce a specified permanent set, usually 0.2%, which is equivalent to a strain of 0.002. The Yield Strength is useful for materials with no Yield Point. The Yield Strength can be determined from a stress strain diagram by laying off the specified offset OX on the strain axis and drawing a line XB parallel to OA. The stress indicated by the intersection of XB and the stress strain diagram is the Yield Strength (pt B).
ASTM E8 governs the determination of Yield Strength for Metals.
ASTM D638 governs the determination of Yield Strength for Plastics.