ESDU Fat A.00.02 shows how the R-M diagram for a notched specimen is obtained from one for a plain test piece of the same material. If elastic conditions existed the R-M diagram would be constructed simply; the radial distance from the origin to the curve for the plain test piece divided by the stress concentration factor yields a corresponding point on the curve for the notched specimen. The behaviour of the stress cycle when yielding occurs is illustrated@ the peak stress being limited to the material proof stress. The R-M diagram is then a line parallel to the mean stress axis from the point at which yield initially occurs. Two worked examples show how the method is applied in practice.