Where C10200 Sits in the Oxygen-Free Copper Family
C10200 is the standard oxygen-free copper (OF) grade. Its copper content is 99.95% minimum and residual oxygen is held at or below 0.001%, which is low enough that no meaningful amount of cuprous oxide forms at the grain boundaries. The metal is melted and cast under protective conditions so that hydrogen cannot react with oxygen during later thermal treatment, which is the mechanism behind the embrittlement failures seen with ordinary tough pitch copper after brazing or annealing.
That single metallurgical difference is what makes C10200 a core material in vacuum devices, precision electronic assemblies and high-reliability conductors. It is softer, more ductile and marginally more conductive than the tough pitch grades, and it stays non-magnetic, so it does not disturb the fields around sensitive instruments.
Electrical, Thermal and Mechanical Behaviour
C10200 delivers electrical conductivity of up to 101% IACS by the International Annealed Copper Standard, together with thermal conductivity well above that of ordinary commercial copper. In practice this means lower I2R losses per unit of cross-section and faster heat removal from a sealed package, both of which raise the efficiency and the service life of the equipment the copper is built into.
| Property | Typical Value |
|---|---|
| Copper content | 99.95% minimum |
| Oxygen content | ≤0.001% |
| Electrical conductivity | 100–101% IACS |
| Thermal conductivity | 390–401 W/(m·K) |
| Density | 8.94 g/cm³ |
| Melting point | 1083 °C |
Because the grade is almost free of dissolved oxygen, it can be annealed repeatedly without loss of ductility, which is what allows strip, foil and fine wire to be produced from the same heat of material.
The Relationship Between C10200 and ASTM B111
ASTM B111 is the specification for seamless copper and copper-alloy condenser tubes and ferrule stock. It fixes the chemistry, temper, mechanical properties, eddy-current examination and hydrostatic testing regime that a heat exchanger or condenser tube must satisfy before it is accepted. Oxygen-free copper grades such as C10200 and C10100 are supplied as tube to the general seamless copper tube specifications, principally ASTM B75/B75M for general engineering sizes, ASTM B88 for water service and ASTM B280 where refrigeration cleanliness applies, while B111 governs condenser duty and ferrule stock.
The two documents are therefore complementary rather than interchangeable, and a project that calls for B111 acceptance usually states both the governing tube standard and the grade. Where an oxygen-free base is required for a condenser or vacuum application, C10200 is the grade that carries the acceptance regime, and the purchase order should name both to avoid ambiguity.
| Document | Scope |
|---|---|
| ASTM B111 | Seamless copper and copper-alloy condenser tubes and ferrule stock |
| ASTM B75/B75M | Seamless copper tube in general engineering sizes |
| ASTM B88 | Seamless copper water tube |
| ASTM B280 | Seamless copper tube for air-conditioning and refrigeration field service |
| JIS H3300 | Copper and copper alloy seamless tubes |
| GB/T 1527 | Drawn copper and copper alloy tubes |
Applications Across Electronics, Energy and Aerospace
C10200 is a standard conductor material in high-end connectors, relays and semiconductor lead frames, where the purity of the metal keeps signal transmission stable across a wide frequency band. High-frequency circuit laminates in 5G base stations use oxygen-free copper strip for low-loss signal paths, and the same strip feeds flexible circuit and rolled foil production.
Electronics and communications: high-end connectors, relays, lead frames, RF strip for base station boards and coaxial conductors.
New energy and power equipment: conductive busbars in wind power and photovoltaic inverters, high-current battery interconnects, heat dissipation modules and high-voltage connectors in electric vehicle platforms.
Aerospace and high-reliability systems: rocket engine cooling ducts, satellite waveguide components and vacuum hardware, where the grade keeps useful ductility at cryogenic temperature and resists softening at sustained elevated temperature.
Industrial instrumentation: current shunts, non-magnetic spacers and precision components that must not introduce electromagnetic noise.
Selecting and Verifying C10200
Three parameters decide performance in practice: oxygen content, conductivity, and the process certification that proves how the metal was melted, formed and annealed. A supplier who can document the melting practice, the anneal sequence and the acceptance tests gives a project traceability from melt to finished part.
Fix the grade, temper and product form in writing, and reference the tube or strip standard that governs acceptance.
Require conductivity on the finished temper, not on a reference sample, because forming and annealing change the measured value.
Ask for eddy-current and pressure test records where tube is involved, and for a certificate of analysis tied to the heat number.
Check purity claims against a test method: oxygen content should be reported by an inert gas fusion or equivalent method rather than inferred from conductivity.
Confirm the cleanroom and packing route for anything destined for a vacuum or semiconductor process.
The trend in the industry is toward thinner sections and higher-performance composites. Rolled copper foil for flexible electronics and copper-based composite conductors for high-field magnets both depend on the same low-oxygen base, so demand for consistently pure C10200 is expected to keep rising.
Frequently Asked Questions
Q: Is C10200 the same as C10100?
No. Both are oxygen-free coppers, but C10100 is the electronic grade with copper at 99.99% minimum, while C10200 has a 99.95% minimum. C10100 is specified where the very highest conductivity is required; C10200 covers the great majority of electronic and power applications.
Q: Does C10200 fail in a vacuum?
The opposite. Its low oxygen content means it does not generate steam internally during high-temperature processing, so it is a preferred material for vacuum devices and sealed assemblies.
Q: Can C10200 be soldered and brazed easily?
Yes. The grade has good wetting behaviour and high ductility, so joints can be made by soft soldering, silver brazing or welding, with dry nitrogen purging recommended for critical internal bores.
Q: How is C10200 supplied?
As tube, strip, sheet, plate, bar, wire and foil, in tempers from soft annealed to hard, with refrigeration and medical gas tube grades supplied degreased, capped and nitrogen purged.
Q: What limits conductivity below the theoretical maximum?
Residual impurity elements and the temper condition. Cold work raises strength but lowers conductivity slightly, which is why the temper is agreed before the conductivity value is guaranteed.
Q: Which industries use the largest volumes?
Electrical and electronic equipment accounts for the largest share, followed by power generation and transmission hardware, building services and industrial process equipment.
