About the Aerospace Fasteners

Aerospace fittings

There is a wide range of methods for joining materials, some of which are suitable for general use and others for specific materials or forms of materials. Common methods:

  • Fascinating
  • Screwed
  • Union
  • Welding

Aerospace rivets

This is the most common method for joining laminated materials in airplanes. A hole has been drilled in the sections to be connected. A rivet of a suitable size is placed in the hole and fixed: the tail of the rivet is deformed so that it expands laterally and captures the sides of the hole, holding the material. They can be manually adjusted, but more often an electric riveter is used. Rivets are available with various head shapes, including mushrooms, rivet rivets and countersunk rivets. When access is available to only one side, blind rivets are used. These are hollow rivets that are placed by pulling the mandrel through the hollow rivet on the same side as the head … then the mandrel breaks. Because blind rivets are hollow, they usually need to be sealed separately. The rivet is pressed into the perforated hole, and then placed: the tail is deformed so that it expands to the side. A deformed tail holds the sheets together and holds the rivet in the hole. A blind rivet can be used when access is limited to one side. Pulling the mandrel through the rivet, the rivet expands to secure it, and the mandrel breaks, leaving a clean cover. Blind rivets are hollow and must be closed after installation if sealing is required.

Aerospace fittings

There is a wide range of special rivets, each for a specific application. Aerospace fittings can be made of any deformable material, but light alloy rivets are almost universal. An exception is the high shear rivet, in which a steel shank with an aluminum alloy collar is used to provide very high shear strength, which is deformed during setting and holds the rivet in place. All rivets are designed for shear use and have limited tensile strength.

Aerospace bolts

This is most useful when large shear loads or significant tensile loads occur in the joint. Aluminum bolts are available for cutting, but steel bolts are usually preferable for most applications. In most fuselage applications, the fasteners should be locked so that the nut and bolt do not loosen in case of vibration or temperature changes. A variety of methods can be used, including cotter pins, wire lock and rivet nuts. For bolts installed in blind holes, wire blocking is the most common method.