A common rivet consists of a cylindrical shaft with a head on one end. The rivet is placed into a drilled hole, and the end of the shaft is deformed in such a way to make it expand to about 1.5 times its original width.
This can be accomplished manually, deforming the shaft by pounding it with a hammer, or tools like pneumatic hammers and riveting machines can be used to deform the shaft. Once the shaft is deformed it essentially has two heads and cannot pass back through the hole, keeping the fastener in place.
Rivets, then, are capable of supporting loads along the axis of the shaft but are more beneficial for supporting loads perpendicular to the axis of the shaft.
Manufacturers create many different kinds of rivets to meet the demands of many different fastening applications. The most common type of rivet is a solid, or round head, rivet, which consists of a solid shaft and head. These rivets are used most often because they provide the most reliability.
Solid rivets are used for manufacturing aircraft frames, bridges, cranes, and structures. Other less frequently used rivets include semi-tubular rivets, blind rivets, drive rivets, oscar rivets, and flush rivets along with many other rivet types. These rivets are used for much more specific applications.
Rivets can also be made from many different materials to better meet the specifications of particular tasks. Aluminum, steel, nickel, and titanium are all common rivet materials.