The paper presents the researches to determine the best technologies to improve the lifetime of the corner welding. Generally it is says that the convex corner welding presents high mechanical properties because of the greater area section. The practice activity shows that in fact, because of the stress concentrators, these shapes of the welding are not the best solution. A better shape of the corner welding is the concave one that provides better results in the working conditions. To provide better results of the convex shape corner welding different recondition techniques are known. The paper is focused on fatigue testing performed on different samples realized with different beads on different working parameters. There are studied different reconditioned probes and the results are reported in fatigue curves.