Hydrogen embrittlement in engineering materials presents significant practical and economic hazards and involves various mechanisms that depend on the specific microstructures of a material. In this study, we investigated the evolution of an initially smooth surface of a stable austenitic stainless steel under hydrogen exposure and the its effect on the mechanical properties. The material was electrochemically charged for 120 hours to achieve a significant hydrogen content. The effect of hydrogen on lattice defects and the plastic deformation at the free surface was focused. Based on Vegard's law, an analytical model was developed to calculate the hydrogen-induced resolved shear stresses on the various crystallographic planes. This model explains the formation of slip lines and the occurrence of plastic deformation in the surface region. Nanoindentation was used to evaluate the effect of hydrogen charging and the associated microstructural changes on the hardness and elastic modulus.