An analysis of reliability of cross-bars, elements of bogie castings produced of cast steel, was made. Tensile strength, impact strength and fracture toughness of cast steel in the temperature range from +20 to -60 grades C were tested to carry out this analysis. Tensile strength and fracture toughness under the static loading at the temperature of -196 grades C were also tested. Apart from mechanical tests an analysis of specimens fractures from impact strength tests carried out in various temperatures was realized to evaluate the existing fracture mechanisms. The assessment of the reliability of cross-bars was made by means of the professional computer programme taking into account static and dynamic loads in four different temperatures and various levels of residual stresses.