Since 1952, Mitsubishi Materials has been a trusted leader in high-quality copper rod production. Backed by more than half a century of expertise and advanced manufacturing know-how, we deliver copper rods and wires precisely engineered for a wide range of demanding applications.
At the heart of our innovation is our proprietary oxygen-free copper technology—our core competency. Leveraging this strength, we have developed the ROX^™ series, a premium lineup of oxygen-free copper wires and copper-based alloy wires designed to meet the highest standards of performance and reliability.

In 2000, Mitsubishi Materials achieved a world-first breakthrough by successfully producing oxygen-free copper wire using the SCR process at the Sakai Site of its Osaka Plant. This technological milestone enabled the commercialization of high-quality oxygen-free copper wires and oxygen-free copper-based alloy wires, opening new possibilities for demanding electrical and electronic applications.
ROX embodies this pioneering achievement and represents Mitsubishi Materials' proprietary oxygen-free copper wire rod brand, trusted worldwide for its quality, consistency, and performance.

*SCR: Southwire Continuous Rod

Ultra-low oxygen. Exceptional reliability.
ROX-OF features an ultra-low oxygen content of 5 ppm or less (or 10 ppm or less), dramatically reducing the risk of hydrogen embrittlement compared to conventional tough-pitch copper.
Our proprietary manufacturing control technology ensures a superior surface quality with minimal defects—making it the material of choice for high-precision applications such as rectangular wires and segment conductors*.
From automotive motor windings and commutators to next-generation high-current systems, ROX-OF delivers the reliability, conductivity, and performance demanded by today’s most critical applications.
*Segment conductors are formed by joining divided rectangular wires, enabling higher motor efficiency and enhanced reliability.

Reliable Heat resistance. Proven Long-Term performance.
ROX-AG is a high-performance alloy wire created by adding silver to ROX-OF, significantly enhancing heat resistance without compromising conductivity.
Even in high-temperature environments, ROX-AG maintains its mechanical integrity. The combination of ultra-low oxygen content (10 ppm or less) and silver creates a powerful synergy, ensuring stable electrical performance over time.
With proven results in applications such as commutator segments and motor windings, ROX-AG is the ideal solution for environments where both thermal durability and long-term reliability are essential.

High strength. High conductivity. Built to endure.
ROX-CPH is an advanced copper alloy wire engineered by adding cobalt and phosphorus to ROX-OF, achieving an optimal balance of high strength, high conductivity, and outstanding durability.
Its excellent tensile strength and controlled elongation make it ideal for demanding applications such as automotive wire harnesses, where miniaturization and weight reduction are critical.
ROX-CPH also demonstrates exceptional stability under repetitive mechanical stress, making it a proven choice for robotic cables and dynamic environments requiring long service life. With these characteristics, it also holds strong potential for emerging Physical AI applications, where reliable motion, sensing, and connectivity are increasingly important.