New technologies (like 3D printing) and the increasing use of no conventional materials (like Fiber Reinforcement Polymer - FRP) are changing the construction industry. More effective and efficient structures are needed in order to achieve sustainable projects. Steel construction industry is not outside this modifications and advances. To keep steel construction competitive in the market, the industry needs to adapt to these changes by optimizing its manufacturing and erection processes. In a steel structure, joints determine almost 50% of the total costs (Bijlaard, 2006). This percentage can drastically decrease if some details are avoided, like stiffeners. Nevertheless, the only way to eliminate these components is through a deepest analysis of the joint. This kind of analysis can be slow and expensive hindering the design process. In this context new numerical tools are appearing in the market in order to improve productivity and facilitate the work of structural engineers. These new powerful tools that come from the hands of the world technological advances, must be taken with care and their results must be validated to be able to realize their efficient, but above all, their safety. In this project, the improvement of the design of steel joints is addressed. This goal was achieved through two major tasks. First, an experiment was performed in order to deepen in the knowledge of simple joints when they are used between “I” shape beams and a flexible element like a hollow section face. The use of high strength welds and its implications were tested in the experiments and at the same time the real behavior of the joint was addressed. The new Eurocode 1993 1-8 (2020) contemplates the use of high strength steel and welds in steel practice. Hybrid welds can lead to a more efficient production process. Secondly, numerical analysis, hand calculations following the Eurocode Rules and previous documented experiments (SERICM II) were compared to validate the use of a finite element tool for daily practice structural engineering. The comparison was made in terms of strength and resistance of the joints and it proved that specialized finite element tools can be used in a safe and efficient way. These tools are able to predict in an accurate manner the joint’s resistance according to the Eurocode Rules.