One of the main problems that occurre in the designing process of steel structure is the achieving of a proper connection. By the means of ductility, similar to the case of structures, connections are divided into ductility classes. The estimation of the ductility is based on the plastic rotation capacity of the connection. One of the most important aspects that one needs to take into account when designing a steel structure is the dissipative mechanism of the structure as well as the structural properties of the connection. The accurate estimation of connections structural properties is crucial in order to correctly choose the structural type and the structural analysis scenario to be applied.