The article presents the study of technological sets of multi-purpose machines based on conical P-3 profile connections for accuracy and rigidity. Based on previously constructed mathematical models of P-3 profile surfaces of the shaft and the sleeve hole,we have performed multiple simulations on coupling of conical connection details. We have analyzed the accuracywith which theshaft with the main elements (drills, cutters, boring tools) was installed in the sleeve hole for six coordinates (3 displacements and 3 rotations). Subsequently, the assembled connection was loaded by an external force, allowing to obtainthe value of elastic deformation (a change in the position of the shaft in the sleeve hole) also for six coordinates. In each case, we havecompared the accuracy of mutual positions of the parts ofP-3 profile and round connections bothin the assembly of the connection as well during its operation by an external force. The main conclusions have been also formulated.