<p>Many studies have been reported on crack retardation in structural members and their underlying principles, but most of these focus on changes in crack growth rates due to overstress. However, there has been no research on the fatigue life of structural members considering the size of the plastic zone caused by overstress. This study assumed semi-elliptical surface crack with different crack aspect ratio (As) to evaluate the infinite life of four structural members under overstress. Appropriate overstress generally allowed for infinite life. For As of 1.0, infinite life was determined by the surface crack (c). For As of 0.6 and 0.3, infinite life was determined by the surface crack (c) and crack depth (a), respectively, although there were slight variations depending on the material. An As of 0.1 was determined by the crack depth (a). The infinite life of fatigue crack due to overstress was most significantly influenced by As. Therefore, accurate measurement of the crack size is necessary to evaluate the infinite life of structures under overstress.</p>