Product Spotlight: Billet Series 7075 Radius Arms

Posted By: Superior Staff Published: 05/05/2025 Times Read: 372 Comments: 0

With over two decades of research, development, and real-world testing, Superior Engineering’s replacement radius arms have become the industry benchmark in off-road suspension. Built to thrive in the harshest Australian conditions, each arm is machined from premium materials to deliver the perfect balance of unmatched strength, functional design, and a clean aesthetic. Every detail, from the caster correction to the OEM Bushes; is tested for maximum performance, reliability, and longevity.

Introducing the Billet Series 7075 Radius Arms

Machined from 7075-T6 Billet Aluminium, Superior Engineering's radius arms deliver the ultimate combination of strength, weight reduction, and corrosion resistance. Stronger and lighter than OEM steel or cast arms, they are built to handle extreme levels of twist, impact, and harsh terrain.

Specifically designed for solid-axle LandCruisers and Patrols, Superior Engineering’s Billet 7075-T6 Aluminium Radius Arms offer significant performance and long-term durability. Whether you're hitting tough tracks or touring remote locations, these arms give you the confidence that your suspension won’t let you down.

The Power of 7075-T6 Billet Aluminium

7075-T6 is an amazing alloy that is renowned in aerospace and military applications for its high strength, and fatigue resistance. It has a high zinc content, giving it comparable wear characteristics to steel, yet it is much lighter and has a significantly higher yield strength.

In the 4x4 world, it straddles the line between lightweight and strength, to give an ideal combination for heavy-duty off-road use. It also won’t rust or corrode and reduces unsprung weight, resulting in less wear and tear on your diffs and suspension while contributing to a smoother ride.

Unique 7075-T6 Radius Arms Features

The Superior Radius Arms feature increased thickness over standard arms, enhancing their ability to take a beating. They also retain the use of OE bushes, so installation and maintenance are made simple with no extra modifications required.

Superior manufactures them in a variety of configurations to suit a range of lift heights, so no matter how much ride height you’re running, the steering angles will be optimised for the best possible performance. And just quietly, we reckon they also look amazing thanks to the anodised silver finish.

Material Comparison to Other Radius Arms

When designing Superior Engineering Radius Arms, we look for the best compromise for strength, wear and tear, weight, and material cost. With the 7075-T6 Billet Aluminium we’ve found an ideal cross-section of all the above without having to resort to highly expensive exotic metals.

Thanks to the increased arm thickness, the billet alloy arms offer equivalent strength to aftermarket Bis80 steel and 4150 CRMO H-beam arms, while still being significantly lighter. As for the factory radius arms? Unsurprisingly, they bent at the thought of the competition.

Elemental Resistance

7075-T6 Billet Aluminium won’t rust or corrode, simple as that. And thanks to our anodising process, the arms will not fade or discolour, as is common with painting and powder-coating, so you can retain full confidence that your Superior arms will not only do an excellent job, but they’ll also look good for years of hard wheeling.

Billet Radius Arms Built to Withstand Real Off-Road Punishment

Radius arms, by design, are subjected to a lot of varying forces off-road, so they can’t be made poorly, or they simply won’t last. Not only do they control the forward and backward movement of your suspension but also aid the Panhard rod in suppressing the side-to-side forces. It doesn’t stop there either; they also need to withstand torsional (twisting) forces when offroad.

As you can see, radius arms play a critical role in your suspension system. That’s why strength, durability, and intelligent design are non-negotiable. After years of rigorous testing and real-world abuse, we’re confident that these are the strongest and lightest radius arms available for coil-sprung LandCruisers and Patrols.

7075-T6 Radius Arms Design Features That Matter

The 7075-T6 material is just the start though. It doesn’t matter if your radius arms are made from steel, aluminium, titanium or adamantium; if the initial design is garbage, the performance will reflect. Luckily, we know a thing or two about putting out top-shelf products that not only work exceptionally well but are built to go the distance.

Design

By using the solid billet beam section design, we have eliminated the need for welds or joints, so there are no weak points or stress risers anywhere along the arm’s length. By incorporating the use of a drop box, we can also retain or improve the suspension geometry to significantly increase off-road performance.

Integrated Bushings and Mounts

Because we retain the OE rubber bushes, the handling integrity and performance characteristics of the vehicle are not compromised. Resulting in significant reduction in noise, vibration and harshness compared to aftermarket poly bushes.

Easy Fitting

This approach also ensures installation is as seamless as possible, making integrating the arms into your existing suspension straightforward and simple. In most cases it is a simple bolt-in process, and even if you do choose to go with a drop box set-up to keep your suspension geometry as nice and flat as possible, it still only requires basic hand tools and a bit of know-how.

Why Upgrade to Billet Series?

By precision machining our arms from a single piece of billet 7075-T6 aluminium, we gain a lot of advantages over other aftermarket radius arm replacements. Essentially, we’re guaranteeing three main things:

Strength

Thanks to the Design, Anodising, Manufacturing, and Materials. No matter what type of wheeling you’re doing, the Superior arms are up to the task.

Safety

CNC-machined to millimetre-perfect tolerances, ensures Superior Engineering Radius Arms will perform exactly how you’re expecting them to. And with industry leading design practices, reliability is a no brainer.

Performance

Specifically designed to suit a range of lift heights, it guarantees that your suspension geometry and steering angles are enhanced, giving you the best possible handling and maximising vehicle safety.