The endurance limit of a specific grade of steel is same as its yield strength. The ultimate strength of this grade of steel is twice of its yield strength. A component made of this steel is loaded in tension and unloaded periodically. It is required that the component does NOT fail for at least \( 10^6 \) loading cycles, as per the Soderberg law. Considering a factor of safety of 2, the maximum applied tensile principal stress is: