Abstract: The distribution of load stresses on threads engaged with a standard screw or nut is very unequal. Indeed, the first threads in engagement support a large majority of the load. So if the load is too important, the threads give way and the function is not provided any more by the screw or the nut. In the prior art, threads are known whose depth or pitch varies a lot in order to cause a self-clamping. In particular, the invention aims at optimizing the resistance and the fatigue resistance of the screws by distributing the load at the very best on their threads without causing this self-clamping. It was shown that the control of the pitch variation, within a chosen pitch tolerance, makes it possible to control the stress distribution on the threads. It is possible to determine a different variation for each load case encountered.

Abstract: The distribution of load stresses on threads engaged with a standard screw or nut is very unequal. Indeed, the first threads in engagement support a large majority of the load. So if the load is too important, the threads give way and the function is not provided any more by the screw or the nut. In the prior art, threads are known whose depth or pitch varies a lot in order to cause a self-clamping. In particular, the invention aims at optimizing the resistance and the fatigue resistance of the screws by distributing the load at the very best on their threads without causing this self-clamping. It was shown that the control of the pitch variation, within a chosen pitch tolerance, makes it possible to control the stress distribution on the threads. It is possible to determine a different variation for each load case encountered.