A breakstem rivet is a type of blind rivet that is set by breaking off the mandrel. The rivet has a hollow shaft with a mandrel inside. The mandrel is pushed through the materials being joined, and then the rivet is set by expanding the tail. The mandrel is then broken off, leaving a small, mushroom-shaped head on the rivet. Our breakstem rivets are made of aluminum or steel with a zinc finish. We have many sizes to choose from to best suit your specific application.