ESDU 80028 presents the results of 251 tests on threaded assemblies in which the nominal thread diameter was equal to@ or greater than@ 1.5 inches (38 mm). Of these tests 160 were on simple nut and bolt assemblies and 91 were on a variety of configurations. The data are presented as S-N curves. The results of the simple nut and bolt assemblies have been analysed to show the dramatic variation in fatigue strength resulting from various manufacturing techniques. The remaining tests were on the larger threads (pitches from 2.25 mm (0.09 in) to 12.7 mm (0.5 in)). These showed relatively low fatigue strength when compared with threads less than 25 mm (1.0 in) nominal diameter.