This report summarizes the derivation of high-load, range-low cycle corrections to API 2SK, 3rd Edition studlink and studless chain fatigue curves, and in this respect supplements the derivation of standard fatigue curves reported in API TR 2FC-1, 1st Edition.

In addition, low cycle high load range corrections to API 2SK's independent wire rope core (IWRC) and spiral strand (SS) wire rope fatigue curves are proposed, and polyester rope fatigue data is reviewed and compared to the recommendations presently contained in API 2SM, API 2SK, and ISO 19901-7.

The proposed corrections to the API TN curves and chain and polyester fatigue test data are provided; where the lower part of the piecewise linear TN curves (in the log-log space) are the same as in API 2SK, while the upper part is the correction, or change, proposed.