Calculations made at OJSC VNIIMT and FSAOU VO UrFU according to the developed method showed that the rotating shaft of the furnace fan heats up unevenly along the length. The temperature of the impeller hub during operation in the furnace volume is close to the temperature of the pumped gas, and the temperature of the shaft end in the area of the coupling is approximately equal to the ambient temperature. On the example of furnace fan Ц9-55 No. 10 the results of calculation of heating of shafts from steels 45 and 12Х18Н10Т with different thermophysical properties are given. The disclosed materials can be used in designing and designing high temperature fans for heating and thermal furnaces.