Coiled and ready to go

In this article Mike North from Advanex discusses the company’s coil thread inserts and tang and tangless thread inserts for aerospace applications.

A spring is a spring! Well No - although last year, 2018, marked 80 years of spring manufacturing in the Nottingham area, Advanex formerly Entex springs is still flying the flag in this regard manufacturing springs in wire, less than 3mm diameter and pressings of all shapes and sizes and more recently a diversification into deep drawn parts ensuring the company’s future.

One of the company’s sites was originally set up under the Kato name to create springs and metal components for micro floppy disks, producing precision parts in high volumes. Of course, floppy disks are now obsolete, so the manufacturing technology had become futile, which is why Advanex found a different product to specialise in. Investment at the site resulted in a metamorphosis to thread insert manufacturing.

In our ‘Tangless CoilThread’ inserts Advanex found a process allied to its known skills. These were originally developed in Japan and made in very low volumes at a slow speed. Machines were imported to the UK and development commenced. The Nottinghamshire site of Advanex has progressed this process over the last 25 years to make it what it is today. Manufacturing its CoilThread products using bespoke machinery, which has been designed, built and installed in-house, at high speed. The imported machines could make six to ten parts a minute, the latest process with the self-built devices runs at 180 parts a minute at full speed, increasing our capacity immensely.

Adding strength

Wire thread inserts can be used to strengthen existing threads, in components, giving applications a longer life. They are coiled from high-quality stainless-steel wire which is cold drawn into a diamond shaped cross section, formed to the shape of the thread. Once the wire is formed into a helical coil insert and installed into a tapped hole, it provides a permanent and wear resistant thread that is stronger than the original thread in malleable parent material.

Although tanged CoilThread has been on the market for many years these were originally developed as a repair process for damaged threads. However, with the use of light alloys in major industries such as aerospace to reduce part weight making aircraft lighter and more cost-efficient overall, this hastened the demand for this fastening solution – tangless inserts are 40% faster to install.

Advanex pioneered tangless inserts, our ‘Kato Tangless CoilThread’ products are identical in form, fit, and function to the conventional tanged inserts. In-fact, they are identical to tanged inserts in every way except for the method of installation and removal.

<Worldwide reach>

With the Advanex head offices for the varied and diversified range shared between four different geographical areas across Japan, South East Asia, America and Europe, the global market reach for customers is widespread. The Nottinghamshire based division is the specialist unit for CoilThread. Like any other global company this means we work with other global manufacturers, servicing the likes of electronics, automotive, and particularly aerospace. In fact, the majority of Advanex’s production is exported, although there are still plenty of users in the UK.

Our pioneering tangless inserts have been marketed for more than 25 years and have made the company a leader across a variety of industries, including space satellite applications; indeed, our tangless inserts will be used on a Mars Rover module in 2020.

Tangless take-off

When it comes to aerospace manufacturing the industry has used aluminium alloys for many years. This means applications for thread inserts in engine components and interior components is common place. Although the majority of manufacturers still use tanged inserts, the task is to convert subcontractors to use the innovative and time saving tangless process.

One example of tangless insert use is a range of aircraft seating units; the basic skeleton is an aluminium casting that has approximately 60 to 130 inserts on each triple seat.

Smaller aerospace components such as actuators take a lot of load through the mountings and in these applications the insert plays a critical role in the integrity of the part. Additionally, aircraft undercarriages are complicated structures that take massive loading especially on landing, and again the humble insert is an integral component in the build of these parts.

When you sit down on an aircraft anticipating a trip to far flung destinations, you cannot imagine the number of parts that make up the whole structure, let alone the interior fittings, from the fold down table in front of you; to the trolley used by the cabin attendant. The number of individual companies that contribute to the final build is enormous and all are under immense time pressure to manufacture and deliver parts on time.

Both Advanex tangless and tanged CoilThread inserts are precision-engineered products that have been put through rigorous torque, tension, and vibration tests; as well as comprehensive dimensional inspections, and metallurgical analysis in attaining their MIL-SPEC qualifications. So Advanex CoilThread inserts have been thoroughly tested by an independent testing laboratory and are certified to conform to NASM8846 (MIL-I-8846).

Plastic performers

With the increasing need for lightweight aerospace and other transportation parts, more and more customers are turning to plastic and composites as an alternative to heavier metals. Some of the benefits of using plastic, especially injection moulding, allow for greater control, detailed and complex geometry, etc. In addition, galvanic corrosion between the insert and parent material is eliminated.

While plastics are easily machined and lightweight, they come with certain drawbacks when it comes to fastening – weaker threads. Although solid inserts for plastic materials are ubiquitous, CoilThread inserts weigh less and require the smallest boss diameter (minimum required material thickness around the insert) for a given size when compared to any other types of inserts.

For these reasons, Advanex is seeing an increase in the number of customers installing CoilThread inserts into plastic materials. The key to success is hole preparation. Moreover, using tangless inserts avoids having to break-off the tang which can potentially damage the plastic thread in the process.

Additionally, the use of Advanex tangless inserts can save customers as much as four hours of labour per shift, per installer as the installation process is simple and fast and after installation there is no need to retrieve the tang which is broken off in tanged installations. These loose tangs can, if not retrieved, become a major hazard especially with smaller sizes, where the tang can be tiny.

Advanex has been able to extend the range of its tangless inserts in recent years. In fact, we believe we make the smallest inserts available around the world with our 0-80 insert.

This kind of innovation is what differentiates our thread inserts from the competitors in the industry. At Advanex we are constantly developing new products and processes too, such as the newer inserts in the different types of pitch thread.

Tangless versions of the fine pitch inserts have recently been developed and on trial at a division of Europe’s premier aerospace manufacturer. This work provides a massive advantage in terms of the application, and Advanex has even found that an end user is implementing this into materials such ceramic products, which is very rare.

The company using this material consulted Advanex initially to discuss an issue with parts cracking. The team got into action regarding an application process and came up with specialised tooling and a process to reduce the stress on the components during the installation. This resulted in improving production and elimination of scrap for this particular aerospace end user.

https://advanex.co.uk