Self-pierce riveting(SPR) is a cold joining process for fastening two or more sheets of material by driving a rivet through the top sheets and upsetting it, under the influence of a die, into the bottom sheet without breaking through it. The technology can join a stack of aluminum sheets up to 12 millimeters thick or a stack of steel sheets up to 6 millimeters thick.
An alternative to spot welding, SPR does not transmit heat to the product. It forms strong, fatigue-resistant joints without affecting intermediate layers or distorting the materials.