Mechanical joining encompasses a wide variety of techniques for securely assembling together two or more geometrically defined parts. This article summarizes the advantages and disadvantages of mechanical joining. It describes the types of mechanical joining methods: those that require one or more additional fasteners to complete the joining process, and those that do not. The article discusses the joining by combining, joining by forming, and joining with fasteners. The advantages and limitations of threaded fasteners, as well as the materials and mechanical properties of common threaded fasteners for aluminum are presented. The article concludes with information on miscellaneous fasteners that have been developed for mechanically joining components.