The basic objective of this investigation is to determine the effect of loading and the shape of the stress-strain curve on the stress intensification factors of Markl’s fatigue evaluation method for metal piping. Markl’s method is based on the fatigue testing of cantilever piping. Subsequent testing using a four-point loading showed that the S-N data were different from that predicted by the equation developed by Markl.Previous analytical work on this topic [1] showed that these differences should occur from cantilever and fourpoint tests. The basic assumption in this analytical comparison is that strain-cycle correlations lead to the correct fatigue life. Given an alternating strain, both types of testing lead to the same predicting of fatigue life using strain-cycle correlations.