C10100 vs C10200 vs C11000 copper
How oxygen-free electronic (OFE), oxygen-free (OF) and electrolytic tough pitch (ETP) copper compare, and which one to specify for busbar and rod.
Side by side
Reference values for each grade. Final specifications are confirmed with each order.
| Property | C10100 OFEWhat Rearden makes | C10200 OFOxygen-free | C11000 ETPMost common grade |
|---|---|---|---|
| Also called | Oxygen-free electronic | Oxygen-free, often sold as OFHC | Electrolytic tough pitch |
| Minimum copper | 99.99% | 99.95% | 99.90% |
| Oxygen | 5 ppm max. | 10 ppm max. | 200–400 ppm (typical) |
| Electrical conductivity (annealed) | 101% IACS min. | About 101% IACS | 100% IACS min. |
| H₂ or reducing-atmosphere brazing | Yes, no embrittlement | Yes, no oxide to react | No: embrittles above ~700 °F (370 °C) |
| Laser or electron-beam welding | Sound joints, no oxide porosity | Low porosity | Porosity risk |
| High vacuum and electron devices | Suitable: low outgassing, covered by ASTM F68 | Acceptable for many uses | Not recommended |
| Bar standard | ASTM B187 | ASTM B187 | ASTM B187 |
| Relative cost | Highest | Middle | Lowest |
Which grade to specify
C10100 OFE
When the part will be brazed in hydrogen, laser or electron-beam welded, plated, bent tight or used in vacuum, or when the drawing calls for OFE.
C10200 OF
When the drawing calls for oxygen-free copper at 10 ppm. C10100 meets that chemistry too, so we can supply and certify against a C10200 callout.
C11000 ETP
When the bar is cut, drilled, bolted and left alone in still air. If none of the conditions above apply to your part, ETP is the economical choice.
Common questions
Is C10100 the same as OFHC copper?
OFHC is a trade name for oxygen-free, high-conductivity copper, most often used for C10200. C10100, also called OFE, is the higher-purity grade, with 99.99% copper and 5 ppm oxygen maximum.
Can C10100 be supplied against a C10200 callout?
Yes. C10100 meets the C10200 chemistry, and we certify against the grade on your drawing, reporting the measured values for your lot.
Is conductivity the reason to choose OFE?
Usually not. At room temperature, OFE and ETP conductivity are close: 101% against 100% IACS minimum. The difference is oxygen, and how the metal behaves when you braze, weld, bend or draw it.
Why does oxygen cause hydrogen embrittlement?
In ETP copper, oxygen sits as cuprous oxide (Cu₂O) at the grain boundaries. In a hydrogen atmosphere it reacts to form steam, which opens voids and cracks. OFE copper has no oxide to react.
Which ASTM standards apply?
ASTM B187 covers copper bus bar, bar, rod and shapes. ASTM B49 covers copper rod for electrical purposes, the feedstock for wire drawing. ASTM F68 covers oxygen-free copper for electron devices.
Not sure which grade you need?
Send us your drawing or your application and process, and we will recommend the grade. Final specifications are confirmed with each order.