ESDU 83012 presents graphically as stress versus endurance curves (S-N curves) the results of some 500 constant amplitude fatigue tests on titanium alloy screw threads to provide fatigue strengths at room temperature@ at elevated temperature and at room temperature after soaking at elevated temperature. The titanium alloys covered are Ti-4Al-4Mn@ Ti-5Al-3Mn@ Ti-6Al-4V@ Ti-6Al-6V-2Sn and Ti-7Al-12Zr plus a limited amount of data on Ti-8Al-1Mo-1V. The thread forms included UNF@ ISO metric@ BSF and BA. Some data on the effects of zinc plating or anodising the Ti-4Al-4Mn threads are included.