[en] Friction welding is widely used as a mass-production method in various industries. Welding is used for joining parts with equal and/or different diameters. Austenitic-stainless steels are preferred over other stainless steels due greater ease in welding. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed austenitic-stainless steels. AISI 304 austenitic-stainless steels having equal and different diameters were welded under different process parameters. Strengths of the joints having equal diameter were determined by using a statistical approach as a result of tension tests. Hardness variations and microstructures using scanning electron microscope (SEM) analysis in the welding zone were obtained and examined. Subsequently, the effects on the welding zone of plastic deformation was analysed. It has been established that plastic deformation of AISI 304 austenitic-stainless steel has neither an effect on the process nor on the strength of the welding joint