Stanley Sees a Riveting Future for Mixed-Material Parts

Stanley Engineered Fastenings (SEF) is expanding the capabilities of its North American headquarters in Troy, Mich., to include the company’s self-piercing rivet technology for aluminum and mixed-material parts applications that carmakers are adopting to reduce vehicle weight and improve fuel efficiency. The 70,000-sq-ft campus includes engineering, manufacturing and sales offices.

SEF, which is part of power-tool giant Stanley Black & Decker Inc., is one of only a handful of suppliers that provide the specialized tooling and rivets used in self-piercing systems. The company has used the technology in Europe for several years.

Mixing materials presents some major bonding challenges, Stanley notes. This includes the compatibility of physical characteristics, such as the varying melting points of aluminum and steel, and the galvanic issues often solved with insulating layers at the joint. SEF says riveting overcomes these issues and doesn’t generate the heat of arc welding that can affect hardness and corrosion coating.

The rivets are driven into a joint with an electric drive, backed by a C-shaped die, which cycles in less than two seconds. The force of the electric punch that sets the rivets is tightly controlled so the rivet flares out to secure the joint without the need of a pre-drilled or punched hole.

SEF says its system, which can be used for aluminum, composites, plastics, steel or combined materials, is used in several European models. One of the largest programs is Jaguar Land Rover’s aluminum-bodied Range Rover luxury SUV, which uses some 4,000 rivets.

SEF also formed a new group last year to develop next-generation fastening systems for automotive applications. One technique being pursued would use robotic arms to change fixtures automatically.