Very few stand-alone sheet metal components are used as a final product by themselves. Usually, a final product appears after joining one or more parts in a sheet metal product assembly. They may be fixed permanently or temporarily. A good amount of detailing goes before the realization of a final product. A flawless mating of two parts begins at a conceptual level. An innocuous hinge may have involved in-depth work with respect to matings and tolerances.
A frequently used product may have a number of parts and joints which must be durable.These may be permanent or non-permanent whose choice depends upon the nature and function of the final product. Two parts may be fixed permanently together either in a rigid way or in a flexible manner. This chapter takes a review of these aspects.