Rivets are mechanical fasteners used to join two or more pieces of material together. They are typically used in situations where welding or screws may not be suitable. Rivets consist of a cylindrical shaft with a head on one end and a tail on the other. To fasten materials, the rivet is inserted through aligned holes in the pieces being joined, and the tail end is then deformed or “bucked” to create a second head, forming a permanent connection.