What type of manufactured head of solid rivets sits above with the surface of the material once it is installed?

The correct choice is the type of rivet that is designed with a protruding head, which means that once it is installed in the material, the head of the rivet sits above the surface. This design is advantageous in applications where additional surface area is needed for load distribution or where a strong mechanical connection is required without the need for a flush finish.

In contrast, the flush head rivet is designed to sit level with the surface of the material, providing a smooth finish typically used in aerodynamics to minimize drag. The countersunk head rivet, similar to the flush head, is also intended to be level with the surface but has a conical shape that allows for a recessed installation. The flat head rivet, while somewhat similar to the protruding head rivet, does not typically provide the same height above the surface.

Understanding these distinctions helps in selecting the appropriate rivet type for specific applications, ensuring both structural integrity and aerodynamic performance.