The objective of this work is the improvement of his thesis, focusing only on the process to find the stiffness equation since only works for steel and obtain an equation that works for the majority of common materials used in industry. For these equations, we will use the Abaqus program, as Giuliano [1] made in his work and the result of the simulations introduces in a Matlab program to obtain these equations. In the second chapter of this work methods will introduce to find the strength to be exercised in a threaded connection and on self-loosening of bolted joints. The third chapter focuses on the different methods that have been published on how to obtain the stiffness of clamped materials and the conclusions that have been reached. The next chapter will talk about the Abaqus´ program and the changes that have to be made in the above argument to obtain simulations of different materials and finally in the last chapter will talk about the results and conclusions.