In case of numerical analysis of forged parts, it is important to specify the friction coefficient characterizing the lubrication conditions. In our paper we present a combined method of a known SU (Simple Upsetting) deformation with EDS (Energy Dispersive Spectroscopy), which shows the relationship between the Kudo's friction number (this friction model is applicable for metalworking processes which produces high surface pressure) and the theoretical layer thickness of the graphite film covering the sink cavity. The tests were accomplished considering the solids content of non-synthetically produced lubricant concentrates diluted to varying degrees.