# UNS C10100 copper

Specify oxygen-free electronic copper by product standard, form and temper; interpret purity, conductivity and processing data without transferring supplier values across conditions.

Reviewed: 2026-11-01

Tags: materials, copper, c10100, oxygen-free-copper, conductors

## Identify the material and delivered condition

KME's **annealed Cu-OFE strip** gives **58.6 MS/m (101% IACS) typical at 20°C**. The separate Aurubis **PNA 203** sheet applies conductivity to the **soft condition**. Its narrative says **minimum 101% IACS**, while its physical table shows **≥100% IACS**. Confirm which limit and test apply to the order. [KME typical strip data](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-OFE_01_2021_e.pdf), [Aurubis PNA 203 narrative and table](https://www.aurubis.com/dam/jcr:411b63c7-fe07-4508-ba63-027cf5083f30/PNA%20203_Cu-OFE_C10100-E.N-%5BRP%5D.pdf)

**UNS C10100** is oxygen-free electronic copper, commonly described as **Cu-OFE**. Aurubis lists **CW009A** as a comparable EN designation, minimum copper **99.99%**, and oxygen below **5 ppm** for its Cu-OFE material. The designation identifies a material family; it does not specify the delivered dimensions, temper, surface or inspection. [Aurubis Cu-OFE sheet, EN_2026_01](https://www.aurubis.com/dam/jcr:411b63c7-fe07-4508-ba63-027cf5083f30/PNA%20203_Cu-OFE_C10100-E.N-%5BRP%5D.pdf)

## Conductivity is a condition-dependent property

KME's Cu-OFE strip sheet gives **typical annealed values at 20°C** of **58.6 MS/m**, **101% IACS** and **394 W/(m·K)** thermal conductivity. These values belong to its stated material and condition, not every manufactured C10100 part. [KME Cu-OFE physical properties](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-OFE_01_2021_e.pdf)

Cold deformation and grain size affect the conductivity of Aurubis's product. [Aurubis conductivity note and table](https://www.aurubis.com/dam/jcr:411b63c7-fe07-4508-ba63-027cf5083f30/PNA%20203_Cu-OFE_C10100-E.N-%5BRP%5D.pdf)

IACS is a conductivity reference scale, not a copper purity percentage. Record measurement temperature and whether a value is nominal, typical or guaranteed. Do not use room-temperature bulk conductivity as a finished busbar's current rating: cross-section, joints, cooling, allowable temperature rise and installation conditions also belong in that assessment.

Kanthal's conductive-wire sheet gives **0.017 Ω·mm²/m resistivity at 20°C**, with guidance limited to its supplied materials. As an original calculation using that rounded value, a uniform **1 m length with 10 mm² cross-section** has `R = ρL/A = 0.017 × 1/10 = 0.0017 Ω`, or **1.7 mΩ**. At an assumed 10 A, `I²R = 0.17 W`. This excludes contacts and temperature rise; it is a resistance/loss illustration, not an ampacity recommendation. [Kanthal wire physical data](https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/conductive-wire/cda-10100-copper/)

## Temper and form control mechanical behavior

KME's **EN 1652 strip** table illustrates the effect of delivered condition:

| Condition | Tensile strength Rm | Minimum elongation A50mm |
| --- | --- | --- |
| R220 | 220–260 MPa | 33% |
| R290 | 290–360 MPa | 4% |
| R360 | ≥360 MPa | 2% |

Keep these strip entries with their standard, gauge length and supplier scope. They are not a universal rod, plate or forging table. KME requests confirmation of specifications before commitment. [KME mechanical table and disclaimer](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-OFE_01_2021_e.pdf)

Choose the delivered condition for the actual forming and service requirements. Establish bend direction and radius, springback allowance and post-process acceptance with the fabricator. Do not translate an R-condition to a differently defined temper system using only a similar tensile number. For design, distinguish tensile strength, yield/proof strength, hardness and elongation; they are different acceptance quantities.

Kanthal separately lists **455 MPa hard** and **220 MPa annealed** for its wire offering. This is another supplier/form example, not a reason to override the strip table or assign an unspecified hard temper to a purchased component. [Kanthal mechanical data](https://www.kanthal.com/en/products/datasheets/material-datasheets/wire/conductive-wire/cda-10100-copper/)

## Processing and joining

Aurubis connects its oxygen-free chemistry with resistance to hydrogen embrittlement and good formability and joining behavior. Keep that material characteristic separate from qualification of a particular furnace atmosphere, braze cycle or weld. [Aurubis material description](https://www.aurubis.com/dam/jcr:411b63c7-fe07-4508-ba63-027cf5083f30/PNA%20203_Cu-OFE_C10100-E.N-%5BRP%5D.pdf)

KME rates cold forming, soldering, brazing and gas-shielded arc welding favorably, while describing machining and resistance welding as less suitable. These are comparative fabrication ratings, not process settings or joint-strength guarantees. [KME fabrication guidance](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-OFE_01_2021_e.pdf)

For machining, qualify tooling, chip control, workholding and inspection on the actual stock condition. Define burr and surface acceptance at contacts, seals and vacuum surfaces. Do not transfer a free-machining copper alloy's cutting behavior to high-purity copper.

For joining, specify the process, filler/interlayer if any, cleaning, thermal cycle and inspection. Determine the resulting condition around the joint rather than retaining the parent stock's mechanical properties throughout the assembly. Recheck conductivity or contact performance where the design depends on the completed process. Thermal processing should be evaluated against both mechanical and electrical requirements.

## Service and release boundaries

Specify chemical exposure by substance, concentration, temperature, flow and duration. An atmosphere or water-service description does not establish compatibility with every coolant, cleaning bath or corrosive gas. For vacuum use, qualify the cleaned assembly, coatings and joints as well as the parent material; the name OFE does not certify a completed chamber or feedthrough.

Release records should retain manufacturer, heat/lot, product specification, form, temper, dimensions and required test results. Keep supplier data separate from lot certificates and demonstrated part performance. Review substitutions when purity, oxygen content, conductivity or joining behavior is an application requirement.

Sources reviewed November 1, 2026. The current Aurubis PDF prints **EN_2026_01**. KME's PDF prints **C10100 - Cu-OFE_10_2020**, despite its filename containing 2021. Kanthal's web sheet states **updated 2019-08-30 08:39**; no timezone is provided.

## Related reference

[Grades, conditions and material selection](../grades-tempers-and-conditions.md)