Heat flows in machine tool assemblies are very complex due to the large number of parts included in their design. Therefore, heat flows are formed not only by the propagation of heat from sources through solid parts, but, to a significant extent, through the contacts of parts between them. Imperfection of the contact at the interface of the separation of solids leads to the appearance of contact thermal resistance (CTR). Taking into account CTR in thermal models makes it possible to reasonably control heat flows in particularly precise assemblies of metal-cutting machines through design and technological measures. The accuracy of the spindle assemblies (SA) determines the accuracy of the machine as a whole by 80%. The thermal errors of metal-cutting machines account for 40-70% of the total error balance, therefore, heat flow control in the SA is very relevant. In the proposed method the sequence of stages for developing a finite element model of the SA temperature field using large-block finite elements is determined; the choice of the thermal model type and its division into large-block finite elements (FE) is substantiated; the thermal resistances of FEs and the heat dissipation capacities in the bearings of SAs are calculated; the equations of the equilibrium of heat flows in the KE assemblies of the thermal model with the choice of initial data for calculations are proposed. The proposed technique using large-block finite elements of the thermal model makes it possible to determine the temperature practically at any point of the structure.