ESDU Fat E.07.03 provides graphs derived from the R-M diagram of ESDU Fat A.00.01 showing alternating stress plotted against endurance for a range of values of mean stress/tensile strength, each graph applying to a value of the exponent m. The curves are based on the mean curve of ESDU Fat E.07.01. Ranges of values of m are suggested for naturally-aged Al-Cu-Mg and for artificially-aged Al-Cu-Mg and Al-Zn-Mg. The curves apply to unnotched specimens but a method is suggested for using them when a stress concentration is present.