PNNL

Abstract

The application of thread-forming fasteners (TFFs) in net-shaped die-cast holes of lightweight metal alloys is being explored by the United States Automotive Materials Partnership (USAMP) through work at the Pacific Northwest National Laboratory (PNNL). These fasteners are being applied in drilled hole applications for general assembly which have reduced costs, reduced investment, and improved warranty while delivering better joint properties. Successful development of this idea in light-weight alloy die-cast products will expand the use of lightweight materials due to the proven benefits already achieved in existing applications. A portion of this effort has included a parametric study of the relationship between joint strength and as-cast hole geometry in aluminum alloy A380 test specimens.