As a result of research of assembly processes of cylindrical parts set by interference fit, admissible failure in assembly position of mutual layout of detail axes was defined, which provides choice of basing schema needed for accuracy and choice of method for reaching of connection accuracy. The Doctorate Paper offers the most appropriated methods for basing and fixating of cylindrical details in automated assembly lines. Model of cylindrical parts set by interference fit was developed by using 3D regular case field theory in description of surface. It was defined that from standardized parameters of surface roughness, value of interference and pressure of contact is affected by Ra and Sm. Basing on 3D contact model, new method of engineering calculations for cylindrical parts set by interference fit was elaborated. The method includes proportion of surface roughness parameters Ra and Sm. It provides the possibility to obtain more accurate and more realistic calculation results in comparison to method developed by S. P. Timoshenko. There was made an experiment with aim to compare the interference obtained in the experiment with the calculated one, by the developed method of engineering calculations for cylindrical parts set by interference fit; and, conclusions were provided.