In this report an account of the experimental equipment, methods of measurement and evaluation of the coefficient of friction and the heat transfer coefficient on bundles of finned rods is given. Taking the conceptional possibilities of the HWGCR fuel elements into account the following two types of finned rods have been used: the first type with 3 higher fins without any spacers and the second type with 12 and 15 lower fins with spacers. The results of measurements are given in non-dimensional criteria dependent on geometrical characteristics of the bundles. The experiments have been carried out with air in the range of Re = 0,4·10⁵ ÷ 2·10⁵.