Abstract: A method for producing machined parts with curvilinear profiles allows for selection of the optimum rotational frequency of a part to be machined by analyzing wave process energy created by interaction of the machining instrument and the machined part while creating the curvilinear profile. During preliminary machining at several rotational frequencies, integral values of the wave process energy are determined and the relationship between these values and the rotational frequencies are identified. The optimum rotational frequency is then selected according to the minimum value of the aforementioned relationship. Increased accuracy in selecting the proper rotational frequency reduces wear of the machining (or cutting) instrument and produces higher quality machined parts in a reduced amount of time.