Reprint from Fastener World Magazine, Vol. 165

Perhaps one of the most difficult things to join together are thin metal sheets. The thickness is the problem because it just doesn’t allow successful joining using many traditional techniques. Industries such as automotive and aerospace which heavily rely on thin metal sheets for structure and support have traditionally been the first to adopt new joining methods that work. For example, automotive has perfected spot welding and aerospace the use of solid rivets and other special fasteners. As time has gone by, however, new, lightweight materials have been added to the mix, and traditional joining methods are quickly becoming unfeasible or obsolete.

Automotive OEMs are rapidly evolving their body-in-white designs to include a hybrid make-up of lightweight aluminum castings, sheets, or extrusions, mild steel, and high and ultra-high strength steel components. These hybrid structures magnify an already challenging joining scenario into one of much greater magnitude. In particular, the joining of dissimilar materials like aluminum and steel make most traditional fastening methods, like spot welding, unfeasible.