Examples of Yeild Strength

PHYSICAL PROPERTIES DOE-HDBK-1017/1-93 Properties of Metal A straight line is drawn through Point (D) Figure 5 Typical Brittle Material Stress-Strain Curve at the same slope as the initial portion of the stress-strain curve. The point of intersection of the new line and the stress- strain curve is projected to the stress axis. The stress value, in pounds per square inch, is the yield strength. It is indicated in Figure 5 as Point 3. This method of plotting is done for the purpose of subtracting the elastic strain from the total strain, leaving the predetermined "permanent offset" as a remainder. When yield strength is reported, the amount of offset used in the determination should be stated. For example, "Yield Strength (at 0.2% offset) = 51,200 psi." Some examples of yield strength for metals are as follows. Aluminum 3.5 x 10⁴ to 4.5 x 10⁴ psi Stainless steel 4.0 x 10⁴ to 5.0 x 10⁴ psi Carbon steel 3.0 x 10⁴ to 4.0 x 10⁴ psi Alternate values are sometimes used instead of yield strength. Several of these are briefly described below. The yield point, determined by the divider method, involves an observer with a pair of dividers watching for visible elongation between two gage marks on the specimen. When visible stretch occurs, the load at that instant is recorded, and the stress corresponding to that load is calculated. MS-02 Page 22 Rev. 0