High-purity formulations engineered for exceptional mechanical machinability and peak conductivity.
Standard pure copper (such as C11000 or C10200) offers unrivaled electrical conductivity but exhibits a major engineering drawback: it is notoriously difficult to machine. Due to its high ductility and stickiness, pure copper produces long, continuous chips during CNC milling and turning, causing rapid tool wear, chip entanglement, and sub-optimal surface finishes. To resolve this dilemma without compromising conductivity, material scientists developed C14500 Tellurium Copper.
By incorporating a precise fraction of tellurium (nominally 0.4% to 0.7%), the microstructure of the copper matrix is modified. The tellurium forms microscopic copper telluride (Cu2Te) particles which distribute uniformly. These inclusions act as natural chip breakers, transforming long, gummy curls into tiny, brittle chips. Consequently, the machinability index jumps from a mere 20% (pure copper) to an impressive 85% (relative to Free-Cutting Brass C36000), all while retaining over 93% IACS electrical conductivity.
"Sichuan Kepai New Material Co., Ltd. leads this metallurgical breakthrough, deploying advanced melting systems to maintain tight control over oxygen levels and telluride distributions."
Technical comparison of tellurium copper against other advanced copper formulations manufactured by Sichuan Kepai.
| Alloy Grade (UNS) | Primary Elements | Electrical Conductivity (% IACS) | Machinability Rating | Key Applications |
|---|---|---|---|---|
| C14500 (Tellurium Copper) | Cu + 0.4-0.7% Te + 0.008% P | 93% - 98% | 85% | EV Charging Pins, Plasma Nozzles, RF Connectors |
| C14700 (Sulfur Copper) | Cu + 0.2-0.5% S | 90% - 95% | 85% | Electrical relays, electrical switches, screw machine parts |
| C18150 (Cr-Zr Copper) | Cu + 1.0% Cr + 0.1% Zr | 80% | 30% | Resistance welding electrodes, spot welding tips |
| C17500 (Be-Co-Cu) | Cu + 0.5% Be + 2.5% Co | 45% - 60% | 50% | High-stress electrical switchgear, relay parts |
| C17200 (Beryllium Copper) | Cu + 1.9% Be + 0.2% Co | 22% | 20% | Heavy-duty spring contacts, non-sparking safety tools |
| C54400 (Phosphor Bronze) | Cu + 4.0% Sn + 4.0% Zn + 4.0% Pb | 19% | 80% | High-wear bushings, bearings, spring connectors |
Established in 2017, Sichuan Kepai New Materials Co., Ltd. has developed into a premier high-tech enterprise integrating pioneering R&D, advanced manufacturing, and global sales networks. Our state-of-the-art facility occupies a **9,000 square meter** footprint, supplemented by a modern **1,000 square meter** engineering office space. We operate in the strategic emerging materials sector, directly supporting national initiatives with high-conductivity oxygen-free copper, tellurium copper, silver copper, and dispersion copper.
Positioned strategically in the western area of the Sichuan Guanghan Industrial Development Zone, adjacent to National Highway 108, Kepai profits from robust logistic infrastructure. This position facilitates direct shipping lines globally, providing prompt raw material logistics and efficient distribution pipelines to North America, Western Europe, and East Asia.
How our custom-formulated C14500 tellurium copper functions at the core of major modern technologies.
With high-voltage DC fast chargers reaching outputs of 350kW and higher, thermal dissipation inside the connector pin is a primary concern. The pins must handle massive electrical currents without overheating. Utilizing C14500 Tellurium Copper ensures minimal internal resistance (93%+ IACS) while the high machinability of the alloy permits the carving of intricate internal paths for active coolant flow.
Radiofrequency coax connectors and base station signal pins demand exceptional dimensional tolerances (+/- 0.005mm) to limit insertion loss and intermodulation distortion (PIM). The structural stability of Kepai's tellurium copper prevents burr formation during CNC machining, ensuring perfect signal transmission pathways in critical telecommunication networks.
Plasma cutting nozzles are subjected to extreme electrical arcs and concentrated thermal currents. Tellurium copper acts as an ideal nozzle material because it conducts heat away from the tip immediately (minimizing erosion) and resists sticking from molten slag, extending the lifespan of consumable industrial parts.
Our structured production workflow maintains tight tolerances and metallurgical uniformity across batches.
At Sichuan Kepai, the production of premium tellurium copper follows a precise, sequential technical roadmap. We control the entire lifecycle from scrap-free raw cathode melting through to final non-destructive inspection. The integration of high-precision drawing machines and computerized eddy-current detectors allows us to guarantee zero internal voids and uniform tellurium dispersion across the entire batch run.
Furthermore, our modern metallographic sample lab routinely monitors grain sizes and phase distributions. By checking each billet for uniform alignment of copper telluride, we provide our international buyers with alloys that maintain predictable mechanical behaviors during high-speed automated lathe machining operations.
Smelting
laying-off
extrusion
drawing
straightening
package
eddy current conductance instrument
Chemical composition test room
Metallographic sample polishing machine
Servo Universal Testing Machine
Electronic Universal Testing Machine
Hardness tester
Global manufacturers require reliability in raw material supplies. Operating within Sichuan, China, Kepai leverages direct access to copper deposits and high-capacity industrial electrical grids. This infrastructure ensures production continuity during seasons where other global regions face energy disruptions or supply shocks.
Furthermore, Kepai maintains full compliance with international environmental standards. All exported tellurium copper alloys are rigorously certified to meet RoHS (Restriction of Hazardous Substances) and REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) standards, facilitating integration into automotive supply chains in North America and Europe.
We provide full heat traceability, chemical mill test reports, and third-party certifications (SGS, TUV) upon request. This detailed verification process minimizes quality inspection time upon arrival at our customer’s assembly plants.
Crucial metallurgy questions answered for component designers, engineers, and supply chain managers.
Pure copper (C11000/C10200) is highly ductile and gummy, which leads to immediate tool wear and continuous chip entanglement on CNC lathes. C14500 tellurium copper incorporates small copper telluride particles. These particles act as micro chip breakers, raising the alloy's machinability score from 20% to 85%. This allows manufacturers to machine high-precision components at significantly higher feed rates with minimal tool wear, whilst maintaining over 93% IACS conductivity.
Tellurium copper has good brazability and soft-soldering performance. However, due to the low melting point of the copper telluride inclusions, direct gas-shielded arc welding requires precise heat input control to prevent cracking. For applications requiring high-temperature structural joints, preheating the material is recommended to achieve a stable weld pool.
Non-uniform tellurium distribution leads to hard spots and mechanical inconsistencies. Sichuan Kepai prevents this by deploying induction furnace melting coupled with custom-designed horizontal continuous casting systems. This guarantees a homogeneous mixture. Every production run undergoes non-destructive eddy-current and metallographic analysis to confirm that the copper-telluride particles are evenly aligned throughout the metal matrix.
Both alloys are formulated to maximize machinability. C14500 contains tellurium and offers slightly better overall thermal stability and mechanical toughness. C14700 contains sulfur and is a cost-competitive alternative that is commonly used in less critical high-volume electrical switch components where maximum thermal cycling resistance is not required.
Yes. Our factory has integrated extrusion, cold-drawing, and finishing machinery. We supply standard round rods, hexagonal rods, flat bars, and customized hollow tubes, as well as complex profile geometries based on customer CAD specifications. This helps minimize scrap rates in high-precision CNC machining processes.
We provide comprehensive mill test reports (MTR) detailing chemical analysis (copper, tellurium, and phosphorus content), electrical conductivity measurements, and mechanical properties. In addition, our materials are fully verified by SGS for RoHS, REACH, and ISO 9001 quality system standards.
Explore our expanded range of custom copper formulations developed for specialized industries.
Looking ahead, Sichuan Kepai New Materials Co., Ltd. will continue to focus on raw material research and application in the field of new materials, contributing to the development of the new copper alloy materials industry in China and globally. We look forward to working hand in hand with friends from all walks of life to create a brilliant future together!
Kepai
