Wire thread inserts are a powerful solution in modern engineering, enabling high-performance threaded joints even in challenging design environments.
Where standard sizes suit most applications, there are circumstances where bespoke-sized wire thread inserts offer a distinct advantage, delivering tailored strength, better reliability or integration within highly constrained assemblies.
In order to figure out the best fit for these designs, engineers need an understanding of the key scenarios where custom-sized inserts become essential as well as beneficial.
Tight space constraints in compact assemblies
Modern engineering frequently pushes boundaries with smaller, lighter and more compact designs. Whether it's for aerospace electronics, medical devices or motorsport components, available space is often minimal.
Bespoke-sized inserts allow engineers to specify shorter lengths or smaller outer diameters, reducing the required boss diameter or material thickness. A key example is wire thread inserts with diamond-shaped cross-sections that support minimal wall requirements, but when even more space-saving is necessary, custom sizing ensures a fit without compromising joint strength.
Unusual load conditions or material pairings
Standard insert lengths are based on optimised ratios between bolt tensile strength and parent material shear strength. However, in high-performance or experimental applications, these ratios may fall outside standard assumptions.
If the parent material is unusually weak (e.g. magnesium alloys), or the bolts are exceptionally strong (e.g. A286 stainless), longer-than-standard inserts (e.g. 3D or 3.5D) may be required to prevent thread stripping.
On the other hand, when minimal load is expected and the joint only requires threading for alignment or light-duty fastening, shorter inserts can be used, saving weight and simplifying installation.
Non-standard thread sizes or special threads
Applications in industries like aerospace, defense or specialised manufacturing often use non-standard screw threads. Bespoke inserts enable the creation of reinforced threads that match legacy fasteners, proprietary threads or special thread forms (e.g., trapezoidal or buttress threads). This ensures compatibility with existing systems whilst still enjoying the performance benefits of wire thread inserts.
Enhanced vibration and fatigue resistance in critical joints
Some applications, such as those in aerospace or motorsport, subject joints to extreme vibration and cyclic loading. Custom-sized inserts, especially longer versions, provide increased engagement length, which helps dissipate cyclic stresses and prevents loosening under vibration. When combined with screw-locking features or specialised coatings, bespoke inserts enhance both mechanical and environmental durability.
Repair and retrofit of damage or oversized threads
Repairing stripped or oversized threads in expensive components (like turbine housings or structural panels) requires inserts with custom diameters or lengths to restore thread integrity. In these scenarios, bespoke inserts are machined to match irregular tap dimensions or oversize holes. This is a common use case in MRO (maintenance, repair, and overhaul) operations where scrapping or replacing a component is costly or impossible.
Unique environmental requirements
Depending on the specific environment of an application, custom inserts may also be specified to perform reliably. When these conditions intersect with custom geometry needs, bespoke inserts become the only viable solution.
- High-temperature environments (requiring materials like Inconel-X750)
- Corrosive or marine conditions (requiring phosphor bronze or cadmium-coated finishes)
- Electromagnetic interference concerns (requiring non-ferrous alloys)
Integrate wire thread inserts that balance precision with flexibility
Standard wire thread inserts offer immense benefits, but bespoke-sized variants unlock even greater performance, flexibility and design integration in specialised applications. If your design is space-constrained, non-standard or exposed to extreme environments, then bespoke wire thread inserts may be the best path forward.
KATO® Advanex offers a broad catalogue of standard Tangless® and tanged inserts, but also has the capability to engineer custom inserts for specialised applications. Whether it's adapting to unusual threads, enhancing insert engagement, or fitting within ultra-compact designs, bespoke inserts empower engineers with total design freedom.
To find out more about our innovative line of products and how they can protect your designs against mechanical joint failure, download our guide below.
