The purpose of the study is labor saving, productivity gain of work and ball screws quality design pursuant to the use in numerical control machines. The article is devoted to the problem of automation of the designing of ball screws with return ports. These ball screws are an important element of the mechatronic modules of numerically controlled machines, as they affect the accuracy of linear displacement. Research methods: system-oriented analysis, structural analysis, methods of functional and object-matching programming, simulation. The novelty of the work: a method of three-dimensional parametric simulation of nuts of ball screws and a computation algorithm for a ball screw based on the synthesis of well-known techniques, has been developed. Research results: a software product consisting of modules that together automate the design process of nuts, screws, rigid supports, tilting saddles and ball screw coupling elements, has been developed. Conclusions: the developed methods for calculation of basic ball screw parameters can be used as the algorithmic basis of software products. Since the process for designing ball screw nuts with return ports has been automated, there are grounds for developing automation methods for other types of nuts.