Fastening systems are important in aircraft construction because of the shear number of fasteners used. Aerospace fasteners and fastener tooling or fastener installation tools are critical in the construction process and are often automated for cost-saving.
Fatigue strength is important for safety and durability, particularly in primary structures and assemblies. AN, MS and NAS are all quality standards indicative of strength, but also tolerance, dimensions, and finish. Blind structural fasteners, while historically lacking in strength, are being improved because they offer the advantage that they need access from one side only.
Sealed fasteners that provide a sealed joint are used in wing fuel tanks for example. Composite fasteners are also being developed for the kind of advanced materials that are introduced for applications in an industry at the cutting edge. High strength fasteners for structures are frequently distinguished by the material they are made from, for example, alloy 600 or titanium fasteners. Titanium has the added advantage for aircraft fasteners, that it is light.
Stainless steel clamps have aircraft applications such as worm-screw clamps for use on fuel, oil, air and coolant lines. The worm drive provides uniform clamping pressure without distorting the hose.
Nuts and nut plates and panel fasteners are commonplace in the aircraft interiors industry. Floating nut plates can also be used to fasten to the fuselage of an unpressurised aircraft. Lockbolts and collars are a common method of fastening interior panels because they spread the load across a greater area, large heads and equally large flanges on the collars.
Self-locking nuts do not need a locking device. The most common method of locking comes from the use of inserts. Locknuts are used in high temperature environments or when subject to vibration.
Bolts are used for strength, but if strength is not a requirement, screws are fine.
Pins are used to secure two objects together. Holes are bored in one or both of the objects and the pins inserted. Pins can be straight, tapered, rolled or grooved and provide perfect alignment, holding parts in
absolute relation to one another. They also prevent slippage due to high motion.
Quick release fasteners are another type of fastener used in aircraft interiors, ie removing panels for easy access.
Aerospace hardware can include aircraft tooling generally, not just fastener installation tools.
Bearings are ubiquitous in aircraft, hydraulic actuators (rod end bearings), landing gear and wheels, flight controls (roller bearings), slats, flaps and flight control surfaces (needle roller bearings), joints, hatch and door mechanisms and aerospace fans.
Hydraulic fittings join titanium tube, stainless steel tube or braided steel hose and are usually subject to 3000 psi. or more.
Aerospace gaskets and seals.
Carbon-faced seals are mechanical face seals that mate up to the rotating mating ring, bearing, or shaft. The seal face in the stationary portion provides the low friction wear element that rides on the harder wear
resistant mating surface. Both the seal face and mating surfaces are typically lapped flat, providing a virtually leak tight seal.
Gaskets too have many varied functions among which is metal O-rings, made from a corrosion and heat resistant steel tubing which form tubular sealing rings. They are primarily for sealing fluid systems at
temperatures where the operating conditions are too severe for conventional elastomeric O-ring seals.
AS9100 hydraulic packings are seals for hydraulic cylinders in aerospace use, where durability is a prime consideration. Teflon O-rings cannot be melted and teflon is inert, with a very low coefficient of friction.
By using the latest inventory management systems and demand modelling software, companies in the aerospace hardware sector usually operate on a worldwide scale processing a huge number of orders daily.