Estimation of gap conductance in nuclear reactor fuel rods requires values for thermal accommodation coefficients of several gases on Zircaloy, uranium-dioxide, stainless steel, and other surfaces. These values for Zircaloy-2 have now been obtained by observing cooling rates of a Zircaloy sphere suspended in the several gases. These measurements are on so-called engineering surfaces, and no special attempt other than baking under high vacuum pumping was used to clean the surfaces. It is found, however, that if the recent kinetic theory results of Cercignani and Pagani on heat transfer from a sphere are used, then quite constant values for accommodation coefficients on a range of pressures are obtained.