This paper presents an analysis and optimization of stress distribution on a screw connection with ISO metric thread. According to previous measurements, which were performed in the application, it was shown that the profile teeth at the joint are unequally burdened. The task is to generally show screw connections, make a CAD parametric model of the joint, analyze the distribution of stresses and optimize it by changing or more precisely, increasing the pitch of the nut. Also it is necessary to compare the behavior of the classical and optimized screw connection and create a table of optimized pitch solutions. The performed FEM analysis presented the stress state of the classic screw connection on the selected example of thread M16. It shows and confirms the classic behavior on bolted joints where the first profiles in contact transfers most of the load while other are much less burdened. The assumption is that the increase of nut pitch, or more specifically the existence of certain positive difference between the pitch of the nuts and bolt, the classical behavior of bolted joints can be improved. This was done and it led to a reduction of the maximum von Mises stress for roughly 30%. In this way, stress distribution and fatigue strength of bolted joints has improved. By specifying the corrected pitch size for threads of general application, presented in the work in tables, it is to be concluded that the method is more appropriate for larger nominal diameter of the threads. Sizes of pitch difference, which are quite small, ascent with the increase in nominal diameter and thus acquire sizes that are easier and cheaper to implement.