This book introduces an innovative method for producing toothed parts through cold rotary forging, offering a cost-effective and energy-efficient alternative to traditional techniques like machining and casting. Designed for practical application, it presents a tool compatible with conventional lathes to form externally toothed parts in a single stroke. Through experiments using lead specimens, the book examines the influence of key process parameters-rotational speed, axial feed, and tool inclination-on the forming load. The results demonstrate near-complete material filling of the die cavities, reduced forming loads, and improved production efficiency. With detailed analysis and practical insights, this book is an essential resource for professionals in automotive and machinery manufacturing, as well as researchers in materials engineering and forming technologies.