| There is a wide range of methods of joining | | | | leave a neat fastener. Blind rivets are hollow, and |
| materials, some of which are suited to general use | | | | need to be plugged after setting, if sealing is required. |
| and some which are specific to certain materials or | | | | There is a wide variety of special rivets, each for a |
| material forms. Common methods are:o rivetingo | | | | specific application. Aerospace Rivets may be made |
| boltingo bondingo welding | | | | from any deformable material, but light alloy rivets |
| Aerospace Rivets | | | | are almost universal. An exception is the high-shear |
| This is the most common method of joining sheet | | | | rivet, which uses a steel stem for very high shear |
| materials in aircraft. A hole is drilled through the | | | | strength, with an aluminium alloy collar that is |
| sections to be joined. A suitably sized rivet is put into | | | | deformed during setting to hold the rivet in place. All |
| the hole and set - the tail of the rivet is deformed so | | | | rivets are designed to be used in shear, and have |
| that it expands sideways and grips the sides of the | | | | limited strength in tension. |
| hole, clamping the material together. They may be | | | | Alcoa Fastening Systems has through a series of |
| set by hand, but more often a powered riveter is | | | | aggressive acquisitions the monopoly on this particular |
| used. Rivets are available with a variety of head | | | | industry, on Kaynar fasteners, Tridair fasteners, |
| shapes, including mushroom, snap rivets and | | | | Camloc fasteners and Rosan products. |
| countersunk head rivets. Where access is available to | | | | Aerospace Bolts |
| only one side, blind rivets are employed. These are | | | | This is most useful where high shear loads or |
| hollow rivets, which are set by drawing a mandrel | | | | significant tensile loads will occur at the joint. |
| through the hollow rivet from the same side as the | | | | Aluminium bolts are available for shear applications, |
| head... the mandrel then breaks off. Because blind | | | | but generally steel bolts are preferred for most |
| rivets are hollow, they must generally be sealed | | | | applications. In most airframe applications, the |
| separately. The rivet is pushed into the drilled hole, | | | | fasteners must be locked to ensure that the nut and |
| then set - the tail is deformed so that it expands | | | | bolt do not loosen under vibration or temperature |
| sideways. The deformed tail clamps the sheets | | | | changes. A variety of methods can be used, including |
| together and retains the rivet in the hole. The blind | | | | split pins, wire locking and clinch nuts. For bolts fitted |
| rivet may be used when access is restricted to one | | | | to blind holes, wire locking is the most common |
| side. Pulling the mandrel through the rivet expands | | | | method. |
| the rivet to set it, and the mandrel breaks off to | | | | |