This textbook is intended for students from speciality "Ship Machines and Mechanisms" in Nikola Vaptsarov Naval Academy for the discipline "Mechanics of Materials". It is not a detailed and comprehensive course for this discipline. The author aims to present the content in the most accessible and illustrated way. Besides, all examples aim to show the applicability of the theory in the future work of students, namely the operation of ship machinery and mechanisms. The knowledge acquired in this discipline is a theoretical foundation in the study of special disciplines.