Aerospace Fasteners Common Types and Materials
Fasteners are common assembly parts that may be used to mechanically join two or more components together. With a variety of fastener types available, a number of attachments can be made to accommodate varying assemblies and requirements. Within the realm of aviation in particular, fasteners are constructed with high quality and optimal strength attributes to assist in aircraft construction and repair. On a single Boeing 747-800 alone, half of the 6,000,000 parts used for assembly are fasteners. With the grand importance that such hardware serves for aviation applications, understanding the more common types and materials used can benefit those who work on or with aircraft.
When engineers are designing an aircraft, the choice of fastener for a particular section will often depend upon a variety of factors such as joint exposure, load presence and values, environmental conditions, and much more. As fasteners are commonly used to distribute loads from one structure to another, they are regularly designed with such requirements in mind and varying fasteners will accommodate different load types. Furthermore, weight, tooling, corrosion protection, and cost can also be additional factors that define a choice.
Rivets are mechanical fasteners that are permanent in their installation, and such types commonly serve for securing aircraft skin sections. In their most standard form, rivets feature a head on one end of a cylindrical shaft, and the tail end of the fastener is passed through performed holes of components. With a special tool, the rivet’s tail is upset for creating a second head on the other side of the assembly, locking all parts in place. With its construction and installation, rivets primarily excel at shear loads, though can also support tension loads as well. If the installation area can only be accessed from one side, special rivets known as blind rivets may be used, and they feature an internal mandrel which can be drawn out with a tool to create a second head. As such, a blind rivet only requires access from a single side for its implementation.
Bolts are another common fastener used for aircraft assembly, and they commonly come in the form of threaded shafts with a single head on one side. For their installation, bolts are commonly passed through the preformed holes of components and then paired with a matching nut. With the addition of a nut, axial clamping forces are exerted upon the component, securing the assembly in place. For their use on aircraft, bolts are most commonly implemented in sections where there is a need for high strength. Additionally, general purpose, AN, and NAS bolts are the most common rated bolts for aircraft construction due to their strength characteristics and performance capabilities.
Screws are often compared to bolts for their similarities, most notably their common use of helical threading and metal construction. Unlike bolts, however, screws are capable of self-tapping, meaning that they can create their own internal threading in a component as they are tightened to secure the assembly. With a variety of screw types available, such fasteners may be used on wood, sheet metal, and plastic materials. As compared to the bolt, screws are used on aircraft in sections where there is not a need for high strength.
When procuring the various fasteners that you need, there are a few common material types that provide varying characteristics that may benefit a particular application. Titanium is a common material for hardware fastener accessories, and its strength surpasses steel and alloy steel while remaining lightweight. As such, titanium may be used to replace aluminum in certain instances where permissible. Aluminum still boasts a high strength-to-weight ratio, however, and its affordability makes it a very advantageous material for fasteners. Steel may be used when high strength is needed, but that strength comes at the cost of added weight. Stainless steel and alloy steel are the most common variants, and they may often be found within landing gear assemblies. Lastly, superalloys are special materials that are high-performance, and they are quite versatile in application while capable of withstanding extreme environments. Common aerospace superalloys include iron-nickel-chromium alloy and chromium tool steel alloy.
At Cogent Sourcing, we serve as a leading distributor of all types of aviation tools required for aircraft maintenance. As such, we are your sourcing solution for NRP panel fasteners, hardware fastener accessories, fastener snap parts, and other quality aircraft parts. As you explore our listings, we invite you to fill out and submit an RFQ form for the items that you wish to procure. Upon receiving your request, our team will quickly review and respond to you in 15 minutes or less with a personalized quote based on your individual needs.