Outlook rivets are among the simplest, most reliable, and oldest types of fasteners. Archaeologists have found evidence of solid rivet use dating as far back as the Bronze Age (circa 3000 BCE). These simple devices consist of a solid shaft with a head on one end; once installed, the headless end of a solid rivet is deformed with a hammer or rivet gun to hold it in place. Perhaps the most widely-used style of rivet, solid rivets are utilized in applications where reliability and safety are important.