Abstract
Hereunder is presented a brief report of the experiments that have been made of the effects of working the understressing and coaxing procedures on the two kinds of fatigue-limit, the fatigue-limit for crack-initiation σw1 and the fatigue-limit for failure σw2, on sharply notched specimens of 0.32% carbon steel. The results show that the strengthening effects of understressing and coaxing are apparent for both σw1 and σw2, and these fatigue-limit increments have been compared with the experimental results that have appeared on the smoothed specimens. Measurements of the non-propagating cracks show that cracks have been propagated with stress increment under the understressing and coaxing procedures. This means that the strengthening effects that have been observed at the crack tip are not limited to such sorts.
