Frettingwear proceeds through particle detachment from the contacting surfaces which, while trapped in the contact zone, can affect the frictional and wear response. Ball-on-flat fretting experiments were carried out between steel specimens under gross slip regime. A transition in the coefficient of friction was linked to a critical contact pressure. The microstructure and chemical composition of the thirdbody evolve with the applied pressure. The evolution of the friction coefficient is strongly dependent on the thirdbody properties. The wear is controlled by the applied load and thus the real contact area within the wear track.