page_title: Rivet
section_title: Oscar rivets
hierarchical_section_title: Rivet / Types / Oscar rivets
caption_attribution_description: English: Oscar Rivet shown with mandrel
context_page_description: A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite to the head is called the tail. On installation, the rivet is placed in a punched or drilled hole, and the tail is upset, or bucked, so that it expands to about 1.5 times the original shaft diameter, holding the rivet in place. In other words, the pounding or pulling creates a new "head" on the other end by smashing the "tail" material flatter, resulting in a rivet that is roughly a dumbbell shape. To distinguish between the two ends of the rivet, the original head is called the factory head and the deformed end is called the shop head or buck-tail.
  Because there is effectively a head on each end of an installed rivet, it can support tension loads. However, it is much more capable of supporting shear loads.
  Fastenings used in traditional wooden boat building, such as copper nails and clinch bolts, work on the same principle as the rivet but were in use long before the term rivet was introduced and, where they are remembered, are usually classified among nails and bolts respectively.
context_section_description: Oscar rivets are similar to blind rivets in appearance and installation, but have splits (typically three) along the hollow shaft. These splits cause the shaft to fold and flare out (similar to the wings on a toggle bolt's nut) as the mandrel is drawn into the rivet. This flare (or flange) provides a wide bearing surface that reduces the chance of rivet pull-out. This design is ideal for high vibration applications where the back surface is inaccessible.
  A version of the Oscar rivet is the Olympic rivet which uses an aluminum mandrel that is drawn into the rivet head. After installation, the head and mandrel are shaved off flush resulting in an appearance closely resembling a brazier head driven rivet. They are used in repair of Airstream trailers to replicate the look of the original rivets.
caption: Oscar Rivet shown with mandrel. (Dashed lines depict flare/flange after installation.)
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