Frequently Asked Questions
Clinching is a simple technique for point joining of metal sheets from around 0.5 to 3mm thick, up to a total joint thickness of about 6mm. Clinching is used mainly for high-volume, undemanding applications such as white goods, heating and ventilating parts and automotive components. There, it replaces processes such as resistance spot welding, as well as other mechanical fastening techniques such as riveting.
Compared with resistance spot welding and self-piercing riveting, clinched joints are generally not as strong. With a punch indentation on one side and a button on the other, clinched joints are mainly used for non-visible, non-critical joints.
Typical materials which can be clinched include:
- low carbon and micro-alloyed steels
- zinc-coated, organic coated and pre-painted steels
- stainless steels
- lightweight materials, such as ductile aluminium alloys
Dissimilar material combinations can also be clinched, for example steel to aluminium. As the joint is made by local plastic deformation of the sheets, it is essential that the materials have sufficient ductility to avoid cracking. Harder materials, such as stainless steels, are normally clinched with semi-piercing tooling. The automotive industry, for example, is driven by weight-reduction, and manufacturers are moving towards thinner, stronger materials. This may affect the material's ductility and reduce its suitability for clinching. However, this drawback may be overcome by further optimisation of the process cycle and developments in punch and die design for specific materials and applications.
a) made with circular tool (non-piercing);
b) rectangular tool (semi-piercing)
FAQ: What is clinching?