The goal of this study was to determine the extent, to which beta radiation modified mechanical properties of surface layer on scale of nano meters. The current trend of replacing varying metal products by plastic products leads to lesser weight, but also a decrease of the tear resistance. This can be countered by exposing the material to electron radiation, which causes a creation of 3D network within the polymer structure. This process is an equivalent to heat treatments of metals. Properties of irradiated polyamide (hardness, modulus, deformation work, creep, etc.) were tested by contemporary indentation method (NHT3). This data was then evaluated by OLIVER & PHARR method. The results have shown that modifying the surface layer of polyamide led to a 50 % increase of mechanical properties.