Wet-operated stirred media mills are commonly used in the field of fine and ultra-fine grinding. Depending on the application, there are different mill geometries and mill equipment materials of which the grinding chamber lining and the stirrer are made. Polyurethane and ceramics are frequently implemented materials. Besides the process-relevant effects such as cooling and wear prevention, an energy efficient mill operation is intended, which can be achieved, by using mechanistic stress models. Here, besides the mill geometry, the process parameters, various energy-transfer-coefficients are also determined. In this work, the effect of different mill equipment materials on the mill-related-energy-transfer-coefficient are investigated by experiments while operating different mills only with water and grinding media but without feed material. It was found that the mill equipment material has a significant effect on the power consumption and thus, the energy transfer within the mill as a result of friction between different materials.