clinching

thumb|Clinching phases

In metalworking, clinching, sealed clinch joint or press-joining is a bulk sheet metal forming process aimed at joining thin metal sheets without additional components, using special tools to plastically form an interlock between two or more sheets. The process is generally performed at room temperature, but in some special cases the sheets can be pre-heated to improve the material ductility and thereby avoid the formation of cracks during the process. Clinching is characterized by a series of advantages over competitive technologies: Reduced joining time (the joining time is less than a second) Reduced cost and weight: the process does not involve additional elements such as screws, rivets or adhesives Reduced cost of the machine No pre-holes are required Can be adopted to join different materials including metals, polymers, wood, and composite materials Can be easily automated and does not require qualified workers Eco-friendly: it does not require pretreatments with solvents, acids, and other harmful liquids The mechanical strength of the metal material near the joint is generally increased due to work-hardening Cleanness: the process does not produce flashes or fumes Repeatability Flexibility: the same tools can be employed for a wide series of materials Reduced joining forces