The paper is focused on the numerical models of steel welded supporting elements and their verification using experiment. Currently, for the stress-strain analysis of the elements in supporting structures it is possible to use many commercial software systems, based on the finite element method - FEM. It is important to check and compare the results of FEM analysis with the results of physical verification test, in which the real behavior of the bearing element can be observed. The results of the comparison can be used for calibration of the computational model. The article deals with the physical tests of steel supporting elements, whose main purpose is obtaining the material, geometry and strength characteristics of the fillet and butt welds. Three types of specimens were designed to investigate the state of stress in fillet of butt welds. Specimens were designed to reflect the fact that the stiffness of connected elements has to be higher than the stiffness of the welded joints. It can therefore be assumed that the stress-strain diagram will reflect the behavior of strains and stresses in welds. During the experiments it was monitored the displacement and the resulting force carried into the specimens.