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KATO® Inserts for Aerospace: Application Guide

Posted by Advanex  |  

Tanged and tangless inserts play a pivotal role in aerospace engineering, making mechanical joints intrinsically stronger whilst protecting light metals from a number of environmental and structural challenges. These inserts are more than technical; they're foundational to building aircraft that are lighter and more sustainable. 

This guide illuminates the key steps to installing the perfect wire thread insert for mechanical aircraft components, diving into the nuances of tanged versus tangless inserts and their impact on aerospace design. It also explores how factors like material choice and surface finish can affect structural integrity, combat wear and ensure reduced emissions. 

Tanged vs. Tangless: a strategic decision

Wire thread inserts, both tanged and tangless, are instrumental in integrating light metals like aluminium and titanium in aerospace designs. By evenly dissipating tension and mitigating the impact of wear, these inserts safeguard softer metals against the detrimental effects of stress concentrations and fatigue. As a result, aircraft designs can be lighter, more fuel efficient and bolster sustainability for the next generation of passenger and commercial aircraft. 


Tanged wire thread inserts have long served the aerospace industry with their robust design, lightweighting capabilities and ease of installation. Their protruding tang ensures maximum shear strength through breaking off once optimal installation has been achieved. As a result, light metals can be successfully integrated in aircraft without the risk of fretting fatigue in joints.  

However, the tang on these inserts can unfortunately introduce the risk of foreign object debris (FOD). Each individual tang needs to be retrieved and documented in a thorough process to avoid a significant threat to air travel safety. This process, albeit necessary, results in additional operational steps and costs involved.


Tangless inserts present a unique wire thread insert solution that is devoid of the traditional tang. As expected, this eliminates FOD risks and presents a safer and cost effective alternative for aerospace applications; the absence of tang retrieval translates into lower maintenance costs and a reduction in the potential for catastrophic failure. 

A key example is with joints surrounding aerospace engines where precision is paramount; the presence of a rogue tang could lead to disastrous outcomes, highlighting the value of tangless for mission-critical aircraft joints. Moreover, tangless inserts can be installed and removed extremely quickly with specialised tooling, reducing maintenance costs and bolstering manufacturing productivity to enhance quality outcomes. 

Material selection: the right material for the right aircraft joint

Wire thread inserts come in a wide variety of material compositions to suit the needs of different mechanical joints across aircraft designs. An insert used on an internal engine component will have different needs to one in the frame of the aircraft, hence the need for different materials with specific characteristics. 

  • 304 Stainless Steel - Serves as a baseline for aerospace applications, offering balanced strength, corrosion resistance and thermal capabilities. However, its limitations under extreme conditions requires the consideration of alternative materials for more demanding aerospace environments.
  • Phosphor Bronze - Its superior corrosion resistance makes it ideal for aerospace components that are exposed to salt water and harsh environments, ensuring durability and consistent performance over extended periods.
  • Inconel-X750 - Specifically tailored for high-temperature aerospace environments, such as engines and exhaust systems. Inconel-X750 maintains structural integrity and resists deformation at temperatures up to 1,000° F, catering to the critical requirements of high-performance aerospace applications.

Surface coating: the final step in aerospace joint enhancement

With the type and material of wire thread insert decided, the final step is choosing the appropriate surface finish for your specific aircraft joint. These surface coatings can provide multi-layered benefits, ranging from additional protections to improved installation efficiency. 

  • Cadmium - Offers enhanced corrosion protection and reduces galling, minimising the friction between insert and bolt. This coating is pivotal for components subjected to varying environmental conditions, ensuring longevity and reliability.
  • Silver - Increases lubricity at high temperatures for components that operate in extreme thermal environments. This facilitates smoother operation and contributes to the reduction of wear on mechanical joints surrounding engine and exhaust systems. 
  • Xylan - Provides exceptional resistance to galvanic corrosion, which is commonplace in aerospace designs with a variety of dissimilar metals. This resistance is crucial for preventing the electrochemical reactions that can lead to structural weaknesses and failures in aerospace components

Elevating aerospace engineering with KATO® inserts

The strategic application of wire thread inserts through the informed selection of types, materials and coatings play a fundamental role in advancing aerospace engineering. By addressing the industry-specific challenges of weight, durability and safety, these inserts enhance the performance of aerospace components whilst contributing to the sector’s ongoing pursuit of innovation and efficiency. 

KATO®’s commitment to quality and precision engineering ensures that aerospace designs achieve their full potential, soaring to new heights of reliability and performance. Each of our inserts and tools are in full conformance with military, aerospace, and commercial standards and specifications. All you need to do is find the right one for you, which our team of specialists can help you with.

To find out more about our products or to get additional pricing information, contact a member of our team today.

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