Yield Strength

Since it is physically difficult in practice to determine the exact point, (2) where the stress-strain curve departs from linearity, the point at which an arbitrary offset drawn parallel to the elastic modulus intersects the stress-strain curve is defined as the yield point, (3). The yield strength as commonly applied to copper and copper alloys is the stress which will produce an extension of either 0.20 percent or 0.50 percent under load. It is known as the Yield Strength at 0.20 percent extension or 0.50 extension. Slightly higher yield strengths are recorded for the same material using a greater offset.

Stress Strain Curve