High-purity copper is a critical material in industries where electrical performance and signal integrity cannot be compromised. In demanding electrical and electronic designs, minimizing impurities is vital to prevent material degradation and power losses.
Sequoia Brass & Copper is a trusted copper and brass supplier serving North American manufacturers, fabricators, and industrial buyers. We stock a broad inventory of high-purity copper alloys, processing material in-house to meet your exact engineering specifications and tolerances.
What is oxygen-free copper, exactly? It is a refined copper alloy produced with an oxygen content below 10 parts per million (ppm), which delivers superior conductivity and ductility compared to standard electrolytic grades. This page covers OFC grades, production environments, and industry applications to assist your procurement decisions.
Oxygen-Free Copper: Grades, Forms, Compositions, and Properties
Understanding what oxygen-free copper is starts with its chemistry. Oxygen-free copper is defined by its extremely low oxygen content, typically below 10 parts per million (ppm). This level of purity separates it from standard electrolytic tough pitch (ETP) copper, which contains oxygen in the 100 to 400 ppm range.
The two primary grades are:
- C10100 (OFE, Oxygen-Free Electronic). The highest-purity grade, with a minimum copper content of 99.99%. This grade is the preferred choice for semiconductor, aerospace, and high-frequency electronic applications.
- C10200 (OF, Oxygen-Free). This contains a minimum of 99.95% copper. It delivers excellent conductivity and formability and is widely used in oxygen-free copper wire and oxygen-free copper cable manufacturing
Both grades share metallurgical properties that distinguish them from standard electrolytic tough pitch (ETP) copper. Most notably, their ultra-low oxygen content eliminates the risk of hydrogen embrittlement during high-temperature brazing and welding operations.
Sequoia stocks various sizes of OFC in rod, bar, sheet, plate and tube. Contact our knowledgeable sales team to find out what we have available to help optimize your machining or forming workflows.
Oxygen-Free Copper (OFC) Production
What makes OFC distinct starts in the furnace. Standard copper is refined through electrolytic processes that introduce trace amounts of oxygen. OFC is cast in a controlled, oxygen-free environment, typically using an induction-melting method under a protective atmosphere of hydrogen or an inert gas such as nitrogen.
This controlled environment prevents copper oxide formation during solidification. The result is a grain structure with minimal inclusions and no oxide particles at the grain boundaries. That structural difference has direct consequences: OFC resists hydrogen embrittlement, performs reliably at elevated temperatures, and maintains electrical integrity in demanding duty cycles. This is what oxygen-free copper is at its core: a structurally cleaner material built for applications where standard copper falls short.
The production process is more resource-intensive than standard ETP copper manufacturing, which is reflected in the material’s cost. For critical applications, however, the performance return justifies the investment.
Applications of Oxygen-Free Copper (OFC)
OFC’s combination of high conductivity, low oxygen content, and mechanical flexibility makes it the material of choice across several demanding industrial sectors:
- Audio and signal transmission. Manufacturers utilize oxygen-free copper wire and coaxial oxygen-free copper cable to carry high-frequency data signals with minimal impedance variation or signal distortion.
- Electronics and semiconductors. Fabrication teams specify OFE-grade (C10100) copper for bonding wire and lead frames because it resists outgassing and contamination under extreme vacuum and high-temperature processing conditions.
- Power generation and distribution. Heavy industrial operations employ OFC bus bars and winding wire to handle repetitive thermal cycles and intense current densities without degrading electrical efficiency.
- Aerospace and defense. Engineering teams rely on the material’s high formability and conductivity to meet weight constraints and strict electromagnetic shielding requirements in custom wire harnesses.
- Medical devices. Medical hardware designs integrate OFC into MRI coils and critical diagnostic imaging systems where consistent, predictable electrical performance is mandatory.
Sequoia Brass & Copper’s Oxygen-Free Copper (OFC) Offering
Sequoia Brass & Copper stocks C10100 alloy across a wide spectrum of form factors. By processing material in-house, including custom cutting, precision sawing, and shearing, we ensure your oxygen-free copper order arrives cut to exact dimensional tolerances, reducing setup time on your factory floor.
We understand the compliance requirements of technical procurement. Every shipment can be provided with full mill traceability, material test reports (MTRs), and definitive chemistry certifications to ensure total quality assurance.
Optimize Your Component Performance with Reliable Copper Supply
Selecting the right copper grade dictates the longevity and reliability of your critical electrical assemblies. As a North American industrial supplier, Sequoia Brass & Copper combines massive alloy inventory with precise in-house processing capabilities to protect your supply chain from extended lead times.
Contact our team today to discuss your material specifications, or submit your dimensions directly through our request a quote portal.