Aircraft are built by assembling many smaller parts into a larger product. It is often done using bonded joints on wood and composite structures or riveted joints on metal aircraft.
Rivets are a popular choice in aircraft construction and repair. They are a superior fastener to bolts due to their strength and load transfer properties.
There are a lot of different materials used to make aircraft rivets. These include aluminum alloys, such as 2024-T4, 2017-T4, 2117-T4, titanium, nickel-based alloys, copper, and mild steel or iron.
These metals are rated for strength and driving properties and have various uses. They are often fabricated in different head shapes and sizes.
Rivets are standardized by their head-shaped code and the material or alloy from which they are made. These codes are derived from military standards and National Aerospace Standards systems.
They are identified by a letter or letters following the head-shaped code that indicates the material composition and then by two numbers separated by a dash. These numbers express the rivet shank diameter in 32nds of an inch and the maximum grip length in 16ths of an inch.
Some rivets are specialized for particular uses, such as blind rivets. These can be driven by one person with no bucking bar and do not require the full shear strength of solid shank rivets.
Aircraft rivets, like nuts and bolts, are fasteners that secure two or more materials together. They join skin sections, hold rib sections, and secure fittings.
Rivets are designed to be solid and durable, able to withstand both shear and torsional forces. They can also resist the effects of vibration.
The strength of aircraft rivets varies from part to part and depends on their application. It is because they are fabricated from different alloys, head styles, and sizes.
Solid head rivets are marked by their head shape and by a combination of military standards, the National Aerospace Standard (NAS), and the older classification system known as AN for Army/Navy. They are also identified by an alloy code followed by two numbers separated by a dash.
The size of aircraft rivets determines the strength and integrity of the structural parts they join. The size of the selected fasteners must be proportional to the material being bound and the amount of stress the material is subjected to.
When selecting a rivet for tubular members, choose a diameter equivalent to at least 1/8 the outside diameter of the tube. If one tube sleeve fits over another, select a diameter equal to the sleeve’s inside diameter.
Generally, when a rivet hole enlarges or deforms, it indicates shear failure. If this is the case, remove the rivets and replace them with the next larger size hook.
Rivets are fabricated in various head styles, depending on their installation requirements. Most blind rivets have shank diameters and grip lengths marked on the rivet head. These measurements are typically identified by the first dash number and are measured in 1/32-inch increments.
Sheet metal is joined together with rivets, and they accomplish this by creating a sturdy junction. They are lighter and far more durable than screws.
A rivet’s shaft expands when it is driven through a hole in sheet metal, filling the gap and creating a second head that firmly holds the material. This head is a crucial part of the integrity of the rivet because it prevents the shaft from snapping through the metal when there is sufficient force.
When selecting rivets, aircraft manufacturers must take into account many factors. Some of these are the materials to be riveted, their type and thickness, the needed head style, and the rivet placement.
Countersunk head rivets have a flat top and are beveled toward the shank, so they fit into countersunk or dimpled holes. This type of head is typically used on aircraft that require a smooth aerodynamic surface, such as those on the wings and stabilizers.