[en] Using nanoindentation, we investigate hardening mechanisms in steered arc (SA) evaporated and electron-beam (EB) evaporated molybdenum thin films. Both films have columnar grains, with the column diameters ranging between 22 and 170 nm in the SA films and 30 and 40 nm in the EB films. The Hall-Petch relation is extended out to hardness values between 6 and 12 GPa. Analysis of nanoindentation creep data (creep, load relaxation, and rate change) reveals that, in the SA films, thermally activated glide is rate controlling, and that grain size has little effect on the underlying rate processes even down to 22 nm. There is evidence based on x-ray diffraction (and supported by the literature) that the EB films contain high densities of interstitial loops resulting from argon ion bombardment during deposition. The analysed creep data indicate that these loops affect the thermal activation of dislocations