Rivets are a fundamental fastener type, although they may not be as glamorous as nuts and bolts. Rivets are an easy to install and economical means to assemble two workpieces in a multitude of industries. It is why the metal sheeting of an aircraft fuselage is held together with rivets - not torqued fasteners.

The accompanying video shows a less common, but still important, means of installing rivets between two heavy-duty substrates. First, pre-formed rivets are retrieved from an industrial furnace and placed into a die. The workpieces are held together in their assembly configuration by clamps, a third hand or the operator. Once in position, the operator initiates the hydraulic press, which presses the molten shaft of the rivet into the cavity of the press tooling. This also serves to relieve some of the thermal energy and initiate solidifying of the metal.

Advantages of the hot forged riveting process include homogenized grain structure of the fastener, increased ductility, the elimination of chemical impurities and reduced scale formation. Disadvantages include possible warping of the metal during the cooling process, less precise tolerances and possible chemical reactions between the metal and its surrounding atmosphere.

This type of process would be used for assembly of workpieces in shipyards, modular construction or other applications where steel stock or substrates need fixed joints.

To contact the author of this article, email kharrigan@globalspec.com