The aerospace industry's pursuit of lightweighting is driven by the demands for fuel efficiency and sustainability. But where aluminium and titanium are used for aerospace components, they face challenges, particularly when it comes to mechanical joints. This is due to concentrated wear, corrosion and fatigue faced by aerospace joints in the extreme conditions aircraft operate in.
Wire thread inserts play a pivotal role in the use of these light metals. By structurally improving the integrity of joints, they enable the aerospace industry to overcome key challenges related to wear, fretting fatigue and notch stress concentration.
In this article, we present the numerous advantages of wire thread inserts in lightweight aircraft. We propose a path forward for the aerospace industry to continue to reduce weight, without compromising on performance.
How wire thread inserts create opportunities to lightweight joints in aerospace
Wire thread inserts are an innovative joint solution that sit between a parent material and a fastening element. They adjust radially and axially when a bolt or screw is driven through, dissipating contact tension across the entire length of the fastening element. This increases the shear strength of the joint, reduces wear to the parent material and provides additional corrosion resistance.
Inserts enable the use of lighter metals such as aluminium and magnesium in mechanical joints. Traditionally, these materials have been disregarded for high-stress joints due to their susceptibilities:
- Aluminium has a low fatigue strength and is susceptible to fretting wear, which can lead to cracks in mechanical joints. Wire thread inserts reduce the impact of wear by dissipating tension on aluminium parent materials. Wire thread inserts designed with diamond-shaped wire are able to spread the load of vibration forces throughout the entirety of a threaded hole, reducing the likelihood of cracks developing.
- Magnesium is a reactive metal, making it susceptible to corrosion which is commonplace in aircraft environments. Wire thread inserts help prevent galvanic corrosion and act as a protective layer between the fastening element and parent material. Wire thread inserts can be coated using any number of techniques to further enhance the corrosion resistance they offer to mechanical joints.
- Titanium has a particular weakness to notch stress concentration that can lead to cracking, which is a common occurrence in mechanical joints. Wire thread inserts dissipate these stress concentrations to prevent cracking in titanium parent materials. Available in a variety of materials, wire thread inserts can be chosen to match the strength requirements of almost any application, from the highest strength titanium alloys to the lightest.
Wire thread inserts play a critical role in the aerospace industry's push towards sustainability and efficiency. The reduction in weight directly translates to lower fuel consumption and increased range, making wire thread inserts a cornerstone in the development of more environmentally friendly and cost-effective aerospace technologies.
The maintenance, repair and overhaul benefits of wire thread inserts
Alongside lightweighting, wire thread inserts provide additional engineering benefits for aerospace designs in relation to maintenance, manufacturing and component longevity.
- Mechanical joint longevity - Wire thread inserts are available in various materials and finishes to enhance their performance and lifespan. A key example are phosphor bronze wire thread inserts that provide additional resistance to corrosion.
- Simple repair and maintenance - Wire thread inserts are designed to be easy to repair, replace and maintain. When tapped holes lose their threading or become damaged from galvanic corrosion, they can be installed to reintroduce and enhance the strength of the joint in a short amount of time. Tangless wire thread inserts can also be removed and reinstalled an infinite number of times.
- Quick and easy installation/removal - These inserts are simple to install and remove for components and joints that need regular maintenance. Moreover, tangless wire thread insert designs eliminate foreign object debris, which is a prominent design risk.
KATO®: leading the charge in lightweight aerospace design
The future of lightweight aerospace design is intricately linked to the advancement of wire thread insert technology. By offering a solution that strengthens mechanical joints while facilitating the use of light metals, wire thread inserts represent a key enabler of the aerospace industry's goals for efficiency, performance and innovation.
KATO Advanex stands out in the field of wire thread insert technology, offering products that are specifically designed to meet the rigorous demands of aerospace engineering. Our inserts, including both tanged and tangless varieties, are tailored to address the unique challenges presented by lightweight mechanical joints in aircraft. Moreover, they also come in a variety of materials and coatings, allowing for customisation based on specific application requirements, such as corrosion resistance or thermal stability.
KATO Advanex's commitment to quality, innovation, and customer support positions us as a trusted partner in the aerospace sector's ongoing journey towards a lighter, more efficient future. To find out more about our products or to get additional pricing information, contact a member of our team today.
