The article performs an analysis of a hot die forging process of producing an elongated forging ended with a joggle in a double system realized on a crank press Masey 1300 t, in open dies, in 3 operations. The thermomechanical model of the forging process considering the changes in the grain size and the forging material recrystallization was elaborated with the use of the calculation packet Qform 7. In the first place, an in-depth analysis of the currently realized forging technology was made, with a special consideration of the temperature changes in the tools as well as in the formed forging. Next, numerical modelling of the process was carried out, as a result of which the following were obtained: correct filling of the tool impressions by the deformed material, the temperature distributions for the forging and the tools, the plastic deformation distributions (considering the thermally activated phenomena), the changes in the grain size and the forging force courses. The results obtained from FEM enable a thorough analysis of the forging process, including: the effect of the deformation time and temperature on the grain size in the forging material, which was confirmed by the microstructure examination results.