Bronze, 1 1/8” length, comprising a square shank rivet and square gusset through which it is seated and peened. Viking ships were built hull first, independent of the framing, which was added later to support the deck and masts. That gave the ships great flexibility able to withstand rough seas by flexing and not breaking as would rigid construction. The hull planks were overlapped (lapstraked) and the overlap secured with rivet sand rove fasteners. Conventional ships were built with spikes. This example is from a smaller boat built in the same way as the long ships. Just the second example we have had, the importance of which to Viking culture and conquest cannot be over stressed.