The yield strength anomaly in FeAl alloys can be hidden if thermal vacancies are not minimized through a slow anneal at a relatively low temperature (~400 °C for ~5 days). Further, the yield strength anomaly is not present in systems that use a very low strain rate as the peak yield strength is strain rate dependent and thus, would occur at temperatures too low to observe the yield strength anomaly. Additionally, since the formation of vacancies requires time, the peak yield strength magnitude is dependent on how long the material is held at the peak stress temperature. Also, the peak yield strength has been found not to be dependent on crystal orientation.