Why Are Fasteners Essential Components for Aircraft

To successfully take flight, an aircraft relies on countless components and assemblies to be secured in place. Permanent fabrication methods like welding can be impractical for certain construction tasks due to heat distortion, material incompatibility, or the need for future maintenance and inspection. On the other hand, fasteners provide a reliable and often reversible means of joining components. This guide will explore why aviation-grade fasteners are so essential, covering the common types encountered and design choices that make sure these components perform optimally.

Understanding the Demands Placed on Aircraft Fasteners

Some fasteners are intended to stay in place for the entire service life of the structure, while others are designed so that components can be inspected, replaced, or modified over time. Not all aviation fasteners are created equal, but most are expected to satisfy the following criteria:

High Load Capacity: Aircraft fasteners must be able to withstand vibration, shear, torsion, and tension stresses without failure.
Durable and Lightweight Materials: Primarily, aerospace fasteners are manufactured from high-performance alloys like titanium, stainless steel, Inconel, or aluminum. Therefore, material selection depends on balancing strength, fatigue resistance, corrosion resistance, and weight.
Environmental Resistance: Fasteners need to display resistance to degradation when exposed to extreme temperatures, moisture, salt air, hydraulic fluids, fuel, lubricants, and de-icing chemicals.
Precision Manufacturing and Standardization: Aviation fasteners are produced to exact tolerances under certain industry benchmarks, such as NAS, NASM, and MS, to guarantee interchangeability and compliant performance.

Common Types of Aircraft Fasteners

Bolts and Screws

Bolts and screws are both threaded fasteners designed to provide secure joints, but their forms and applications differ in important ways. Bolts typically feature a partially threaded shank with a smooth, unthreaded portion beneath the head, which is often hexagonal for installation with wrenches. With additional components like nuts and washers, they create a strong clamping force for structural joints subjected to shear and tensile loads.

On the other hand, screws are usually smaller in diameter and fully threaded along their length. Instead of heavy loads, they usually secure non-load bearing equipment like access panels or interior fittings. Moreover, screw heads come in many forms to accommodate different installation and flushness requirements.

Nuts and Washers

Nuts are internally threaded fasteners made to be placed over the ends of bolts, with some notable variations including:

Lock Nuts: Lock nuts feature either deformed metal threads or nylon inserts that create friction against bolt threads, preventing loosening under continuous vibration.
Castle Nuts with Cotter Pins: Made for use with drilled bolts, these nuts have a slotted top for a cotter pin to be passed through the aligned slots and bolt hole, preventing loosening. Castle nuts are especially valuable in assemblies subject to movement or vibration, such as landing gear or control linkages.

Meanwhile, washers are thin, disk-shaped components placed under bolt heads or nuts to improve load distribution and prevent surface damage. They can be widely categorized as either flat washers, which simply provide a smooth bearing surface, or lock washers, which have split or toothed designs that create additional resistance to rotation.

Rivets

Rivets are cylindrical fasteners consisting of a smooth shank and a pre-formed head on one end. The tail end of the rivet is made to be deformed or expanded during installation, permanently locking it in place and spreading the load over a larger area. These fasteners are highly effective for joining the thin sheets of material used for wing skins or fuselage panels, some of the most popular types including:

Solid Rivets: These rivets require access to both sides of a structure during installation, as their heads need to be formed by hammering or using a pneumatic rivet gun.
Blind Rivets (Pop Rivets): Designed with a hollow shank and an internal mandrel, the body of a blind rivet expands when the mandrel is drawn through with a rivet gun. This creates a secure joint without needing access to the other side of the material.

Clips and Clamps

Clips and clamps are both used for organizing and securing assemblies like wiring bundles, hydraulic lines, and tubing. Their purpose is mostly functional rather than structural, helping items remain properly routed, free from abrasion, and accessible during inspection and maintenance. As such, they can either be made from metals or high-strength polymers, depending on how much of a priority saving weight is. Some popular forms include:

Cushioned Clamps (Adel Clamps): Cushioned clamps feature a metal band lined with rubber or synthetic cushioning material.
Spring Clips: These are simple, lightweight clips that use tension to hold lines or wires in place, able to be quickly installed and removed without tools.

ASAP Aviation Unlimited: Your One-Stop Shop for Aircraft Fasteners

In summary, fasteners are essential for creating a secure bond between parts that make up an aircraft, each type having a distinct and vital role to play. Aviation fasteners should never be mistaken for scaled-up versions of standard variants, as they are subject to very strict quality and manufacturing standards. As such, aircraft operators and procurement professionals need to rely on suppliers who can verifiably provide aviation-grade components.

ASAP Aviation Unlimited is a go-to procurement platform for fasteners and hardware, featuring thousands of options for various aircraft models and industry specifications. Everything in our inventory is sourced from trusted manufacturers and suppliers, and we make it easy to secure competitive fulfillment options that are tailored to your needs. With these promises in mind, be sure to check out our database and connect with our experts at your convenience.