This study of the process of chip formation and curling when cutting ductile materials supplements the work of well-known authors in this field. The relevance of theoretical and experimental research stems from determination of the design parameters of chip formation by the flat spiral shape. The study used tools and materials that closely resemble those used in machine repair shops. A distinctive feature of this study is the use of theoretical and experimental data to determine the conditions of chip breaking and to design chip-forming elements on the cutting face of a metal-cutting tool. The obtained results allowed theoretical calculation of the geometrical parameters of a metal-cutting tool in constrained cutting and determination of the areas of chip formation with a high bulk density.