Question: what is .2 yield strength?
Answer: The yield strength is defined as the level of stress that produces a specific amount of permanent set. ... The 0.2% offset yield strength (0.2% OYS, 0.2% proof stress, RP0. 2, RP0,2) is defined as the amount of stress that will result in a plastic strain of 0.2%. This is illustrated by the blue line in Figure 1 below.