Abstract <p>Surface plastic deforming is widely used in various branches of mechanical engineering to improve the performance properties of materials. The results of a study of the influence of surface plastic deformation modes on the structure, microhardness, and magnetic characteristics of the 04Kh17N8T austenitic steel are presented in this article. The experiments include changing the parameter of surface plastic deformation—the normal load on the indenter. Changes in the crystalline structure of the material after deformation are analyzed using microstructural analysis, including optical and electron microscopy. The mechanical characteristics of the samples are determined using a Barkhausen noise analyzer. It is established that the hardness of the samples in cross section is almost the same with an indenter load of 250 N or more. In addition, there is a correlation between deformation modes and hardness. It is shown that changing the modes of surface plastic deformation has a significant effect on the structure and magnetic characteristics of steel. Friction treatment leads to the formation of a gradient structure with a depth of up to 500 μm, while a highly deformed dispersed structure is formed at a depth of up to 25 μm. Due to the increase in the normal load on the indenter during friction processing, the content of defects in the material increases affecting magnetic properties of the material. The obtained results can be used to improve surface plastic deformation technologies and optimize steel processing to achieve the required level of performance characteristics and increase the service life of parts and structural elements.</p>