The sensitivity of the Locati fatigue limit to variation in the test parameters -- stress and cycle increments and initial stress -- was tested statistically. Factorial experiments performed on both carbon steel plate material and high-strength steel wire showed that the Locati fatigue limits differed significantly from those estimated by the "staircase" method. The magnitude of cycle increment and initial stress significantly affected the predicted fatigue limits of both materials. In addition, the predicted fatigue limit of the carbon steel was significantly affected by the magnitude of the stress increment.
"An Examination of the Locati Estimation of the Fatigue Limit," Materialprüfung, v. 11, no. 4, April 1969, pp 109-114.