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Aerospace-Fasteners-Aircraft-Applications

As technology advances, the aerospace industry continues to produce more durable aerospace fasteners, which are crucial for the assembly of commercial and military aircraft, jets, ballistic missiles, and space-bound rockets. This article delves into the types, characteristics, materials, and key roles of aerospace fasteners in aircraft manufacturing

Overview of Aerospace Fasteners

Aerospace fasteners play a critical role in connecting aircraft structures, and they must withstand extreme pressures and temperatures. The production of these fasteners relies on the rapid technological advancements in the aerospace sector.

Definition of Aerospace Fasteners

Aerospace or aircraft fasteners are a type of CNC-machined aerospace parts specifically applicable to the production of aerostructures. Aircraft detail parts are assembled across various production locations rather than being produced in a single plant. These fasteners are essential for joining these parts into a complete airplane during the final aircraft assembly.

The aerospace industry has stringent safety and weight requirements, resulting in high-quality and extremely durable fasteners for aircraft manufacturing.

Fasteners also facilitate the assembly of aerostructures such as fuselages, wings, empennages, noses, pylons, nacelles, flight control surfaces, and more. Moreover, they provide attractiveness and durability to both commercial and military aircraft designs.

Additionally, aircraft fasteners provide rigidity to the aerostructure, making them an essential component of an aircraft. These fasteners come in various types, including nuts and bolts, screws, rivets, and more.

Characteristics of Aerospace Fasteners

Aerospace or aviation fasteners must be highly robust to withstand tremendous gravitational pressures. They are critical hardware that affects the overall safety and efficiency of an aircraft. Moreover, to ensure efficient manufacturing and use, these fasteners must pass stringent standard certification.

These fasteners are used in any equipment that requires high-precision and high-quality attachment. Some common properties of these fasteners include:

  • Operation in harsh conditions
  • High shear, fatigue, and tensile strength
  • Self-sealing and self-locking capabilities
  • High corrosion and oxidation resistance
  • Lightweight design

Aviation Quality Standards

The AS9100 and AS9120 quality management standards are widely used in the aerospace sector. AS9100, BS9100, and EN9100 are standards for organizations designing and manufacturing aerospace goods, such as parts, components, and assemblies. On the other hand, AS9120, BS9120, and EN9120 are standards for manufacturers and distributors of aerospace parts.

Commonly Used Fasteners in the Aerospace Industry

There are various fasteners for aerospace that have broad applications in the commercial aviation industry. Here is an overview of the different types of fasteners used in aircraft and how they compare and differ.

  • Aircraft bolts: Made of unplated corrosion-resistant steel, zinc plated corrosion-resistant steel, cadmium, or anodized aluminum alloys. Commonly used bolts for aircraft include MS bolts, close tolerance bolts, NAS internal wrenching, and AN bolts.
  • Aircraft nuts: Threaded fasteners made of cadmium-plated carbon steel, stainless steel, or anodized 2024T aluminum alloy. Always used in conjunction with a mating bolt or screw. Aircraft nuts come in two types: non-locking and self-locking.
  • Aircraft screws: These fasteners are the most common threaded fastening method with a helical ridge, called an external thread. Often made of lower-strength materials than bolts and inserted with a loose-fitting thread.
  • Aircraft rivets: These fasteners have a smooth cylindrical shaft with a head on one end and are used to join two or more metal sheets, plates, or pieces of material. The rivet’s shank is placed into matched holes in two pieces of material, and the tip is upset to produce a second head that securely clamps the two parts together.
  • Aerospace Collars (Lock Bolt Rivet): These fasteners fit seamlessly with lock bolt rivets (available separately). They aid in attaching the rivet or bolt to the object and have compatible metal alloy bodies.

Special Fasteners Used on Aircraft

These unique fasteners have applications in place of standard AN nuts and bolts and are lightweight with high metal strength. Most Light Sport Aircraft also make considerable use of special fasteners (LSA). Some of the most commonly used special fasteners are as follows.

Taper-Lok

The strongest special fasteners used in aircraft construction are Taper-Loks. They feature a tapered design that enables them to exert force on the walls of the hole. Unlike a rivet, the Taper-Lok fills the hole without deforming the shank.

The washer head nut squeezes the metal against the tapered walls of the hole with considerable force. This forcing of metals together creates radial compression around the shank and vertical compression lines. The combination of these pressures produces a level of strength unmatched by other fasteners.

Hi-Lok

A bead encircles the bottom of the Hi-Lok fastener's shank. This bead increases joint strength by preloading the hole it occupies. It presses against the hole's walls during installation, creating radial stress that reinforces the surrounding area. The joint is not subjected to the constant cyclic activity that causes a joint to work or fail because it is preloaded.

Common materials used to make Hi-Lok fasteners include:

  • Aluminum
  • Titanium
  • Stainless-steel alloys

Its collars come in two types: sealing and non-sealing. They are made from appropriate metal alloys and can be installed with an Allen wrench and a box-end wrench, just like Hi-Loks.

Turn-Lock Fasteners

Turn-lock fasteners secure inspection plates, doors, and other removable panels on aircraft. This aerospace hardware is also known for quick-opening, quick-action, and stressed panel fasteners.

These fasteners allow easy removal of access panels for inspection and maintenance. They are manufactured and sold under various brand names by several companies. Dzus, Camloc, and Airloc are three of the most popular.

Dzus Fasteners

The Dzus turn-lock fastener consists of a stud, grommet, spring, and receptacle, with the grommet made from aluminum or alloy. If grommets are not available from usual sources, 1100 aluminum tubing can be used to form them.

The spring has a cadmium-coated steel body that prevents corrosion. Once two assemblies are linked, the spring provides the force that locks or secures the stud in place.

The studs are made from steel and coated with cadmium. There are three different head types: wing, flush, and oval. The markings on the stud's head are used for identifying or determining the body diameter, length, and head type.

As mentioned before, fasteners for the aircraft industry include both standard and special fasteners, which must meet rigid and rigorous standards to withstand extreme environments. If you are looking for high-quality custom fastener solutions, Unofactory is your best bet. Unofactory is a professional manufacturing service provider that produces high-quality custom aerospace fasteners as well as numerous common fasteners.

We have strong manufacturing capabilities to ensure the shortest lead time for you. We also offer instant quotes and automated DfM analysis for your aircraft fasteners. Feel free to check it out.

What Are Aerospace Fasteners Made Of?

There are various types of fasteners for the aircraft industry, and not all materials are ideal for producing these fasteners. The reason is that the material composition of these hardware determines their characteristics. Below are some materials used for producing different types of aircraft fasteners:

Aluminum

This material is a lightweight metal used for producing various aerospace parts due to its availability and affordability. Although used in manufacturing aircraft parts, this material has some limitations that require additional surface treatment to enhance its properties.

An instance where aluminum plays a role in aircraft fasteners is rivets. This hardware is often cold-formed (producing metal pieces without heat to create highly durable pieces). The Al7075 is the most popular aluminum alloy for manufacturing fasteners due to its high tensile strength and resistance to fatigue.

Steel

Steel is three times stronger than aluminum, but this strength also increases its weight. Since aviation fasteners should be as lightweight as possible, the weight of steel poses a challenge.

There are different types of steel, but for manufacturing fasteners for aircraft, stainless steel and alloy steel are ideal. Their strength makes them better for producing screws and bolts used on aircraft surfaces and landing gear.

Titanium

In the manufacturing of some commercial aircraft fasteners, titanium material could replace aluminum. Also, this metal has a strength comparable to that of alloy steel and steel. Besides, it is lighter than steel and has high heat and cold resistance.

Super Alloys

Their ability to withstand extreme pressure and temperature conditions makes these alloys perfect for use in the aerospace industry. Also called high-performance alloys, they are highly versatile, maintaining their surface and structural integrity in extreme conditions. Below are the superalloys for the aerospace industry:

  • Hastelloy: Has high corrosion resistance. They have applications in the exhaust and combustion components of an aircraft.
  • Inconel 780: High tensile strength alloy for the manufacture of bolts and nuts.
  • A286: An alloy of iron, nickel, and chromium, used because of its high ensile strength, resistance to oxidation, and corrosion 
Now you are aware of the materials used to manufacture aircraft fasteners and their characteristics.Aerospace Fastener Covers

Commercial aircraft fasteners require covers to protect against environmental and atmospheric conditions. A variety of materials can be used to manufacture fastener covers, including:

  • Cadmium
  • Zinc
  • Silver
  • Nickel
  • Phosphate
  • Black Oxide

These covers greatly enhance the durability of fasteners.

Conclusion

Aerospace fasteners are a vital component of any aircraft; without them, the aircraft would simply be unusable parts. This article has provided valuable insights into the fundamental aspects of fasteners used in aircraft construction. Many companies specialize in the manufacturing of these aircraft fasteners, and Unofactory is among them.

Unofactory specializes in CNC machining of aerospace parts and offers instant quotes and automated DFM analysis. For over a decade, we have been manufacturing both standard and custom fasteners for our valued customers. We are pleased to leverage our successful cases to provide you with the best aerospace fasteners and other aircraft hardware. With a team of experts and professionals, as well as fast lead times, you are sure to receive high-quality standards.