Many engineering industries are looking for innovative ways to reduce design weight, improve fuel efficiency and minimise costs. Integrating light metals like aluminium and magnesium are a solution to achieving this, but bring their own challenges. They are softer, have lower tensile strength and are susceptible to mechanical wear.
These challenges are problematic in the use of bolts and tapped holes, with concentrated tension leading to wear, damage and potential failure. Wire thread inserts were invented to solve this challenge by introducing a dedicated fastening element for lighter metals.
In this article, we dive into the challenges of using light metals in the context of joints, and how wire thread inserts have helped engineers overcome them.
The challenges of light metals in mechanical joints
Light metals provide a range of benefits for engineering designs. For aerospace applications, they help improve fuel efficiency and enable greater flexibility with designs. For electric vehicles, lighter metals are vital in maximising battery capacity and extending driving range. So much so that metals like aluminium and magnesium have already been staple materials in both industries for decades.
However, many light metals exhibit a low hardness and poor resistance to mechanical wear. This susceptibility is particularly problematic when it comes to fastening components using a bolt/screw in a tapped hole. Without a fastening element, there are concentrated areas of tension between the bolt and thread known as notch stress concentration. This results in fatigue cracks, which are more prevalent in lighter and softer materials, and can result in mechanical failure of the joint itself.
Wire thread inserts - a solution to light metal integration
Wire thread inserts are a direct solution to enhancing the durability of joints in lightweight components. They were invented in 1936 as an Aero-Thread Screw Thread System for aircraft designs to enable the use of aluminium. They have since become a staple in many industries for the durability and strength they provide for joints and fastenings.
Wire thread inserts are helically coiled diamond-shaped wire with a threaded hole at their centre. They are installed into threaded holes which act as a point of contact between the screw/bolt and parent material. The insert adjusts radially and axially within the parent material, dissipating the tension over the entire hole and minimising the impact of notch stress concentration.
Benefits of wire thread inserts for light metal components
- Enhanced durability - Wire thread inserts provide enhanced durability for light metal joints. This effectively eliminates the risk of notch stress concentration, enabling the integration of light metals into designs without risking mechanical failure.
- Prolonged lifespan - As a result of the enhanced durability of joints, wire thread inserts extend the lifespan of components by reducing the long-term wear within joints. This provides reliable operability of designs for a longer period without the need of maintenance.
- Additional protection - Light metals often show susceptibility to elements other than wear, such as galvanic corrosion. This is the result of dissimilar metals being in contact with the presence of an electrolytic solution. Wire thread inserts can be created in a number of finishes and materials, such as non-passivated stainless steel to minimise the possibility of galvanic corrosion.
KATO® Advanex - wire thread inserts that are trusted across industries
Wire thread inserts enable the reliable integration of light metals in designs thanks to their durable properties. Notch stress concentration, corrosion and other effects are eliminated from joints, allowing designers to effectively optimise the weight of their designs.
KATO® Advanex is the leading manufacturer of both Tanged and Tangless wire thread inserts. They form strong and resilient joints for lightweight metals that also reduce material costs and help increase efficiency. Thanks to their reliability and features, our products can be found in a wide range of industries, from automotive and aerospace to electronics and railway.
To find out more about KATO® Advanex and how our products can help reduce the weight of your designs, contact a member of our team today.
