# UNS C12200 copper

Specifying phosphorus-deoxidized C12200 by product form, temper, conductivity basis, joining route and service requirements.

Reviewed: 2026-11-01

Tags: materials, copper, deoxidized-copper

**C12200** is phosphorus-deoxidized copper, commonly called **Cu-DHP**.

## Identity and chemistry

Aurubis's **Cu-DHP** sheet specifies **at least 46 MS/m (79% IACS) in the soft condition**. KME's rolled product gives **47 MS/m (81% IACS) typical in the annealed condition at 20°C**, with **330 W/(m·K)** thermal conductivity. Confirm delivered conductivity and measurement temperature when either property governs. [Aurubis soft-condition limit](https://www.aurubis.com/en/dam/jcr%3A1c92bc25-e000-4851-a265-1ffe873aee8f/PNA%20219_Cu-DHP_C12200-E.N.pdf), [KME annealed rolled-product data](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-DHP_01_2021_e.pdf)

Aurubis Stolberg's Cu-DHP sheet, marked **EN_2026_01**, lists comparable designations **UNS C12200, EN CW024A and JIS C1220**. It gives **minimum 99.90% Cu** and **0.015–0.040% P**, and explains that residual phosphorus reduces conductivity while the material offers good forming and joining behavior. Treat the cross-reference as an alloy-identification aid, not a declaration that every product standard has identical delivery and acceptance requirements. [Aurubis Stolberg, Cu-DHP material datasheet](https://www.aurubis.com/en/dam/jcr%3A1c92bc25-e000-4851-a265-1ffe873aee8f/PNA%20219_Cu-DHP_C12200-E.N.pdf)

**Unit conversion:** 0.015–0.040 mass% phosphorus equals **150–400 ppm by mass**, because 1% equals 10,000 ppm. This is a range, not a fixed nominal addition or a certificate for a supplied batch. Keep the analytical basis and applicable specification with chemistry results.

Wieland Small Tube Products identifies its Alloy 122 as C12200/Cu-DHP/CW024A and lists multiple tube-related standards and delivery forms. That breadth reinforces a procurement distinction: specifying C12200 chemistry does not choose between a straight tube, coil or fabricated shape, or select the governing product standard. Its undated webpage is not assigned a publication date from its copyright footer. [Wieland Small Tube Products, Copper Alloy 122](https://smalltubeproducts.com/solutions/alloy-diversification/copper-alloy-122-c12200/)

## Product form and temper are part of the requirement

The Copper Development Association's **Copper Tube Handbook**, printed **©2024, publication A4015-24/23**, describes drawn and annealed tube as the trade's “hard” and “soft” conditions. It also distinguishes standard plumbing tube sizing from ACR tube designation: ACR is identified by actual outside diameter. Preserve tube type, actual dimensions, wall thickness and temper rather than assuming a nominal size specifies them all. [CDA, Copper Tube Handbook, Standard Tubes](https://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf)

For rolled products, Aurubis Finland's undated Pori Cu-DHP sheet separately reports these conditions:

| Condition | Tensile strength Rm | 0.2%-proof/yield entry | Elongation A50 / A |
| --- | --- | --- | --- |
| H040 / R220 | 220–260 MPa | Maximum 140 MPa | Minimum 33 / 42% |
| H065 / R240 | 240–300 MPa | Minimum 180 MPa | Minimum 8 / 15% |
| H090 / R290 | 290–360 MPa | Minimum 250 MPa | Minimum 4 / 6% |

The elongation heading separates **0.1 to less than 2.5 mm** thickness from **2.5 mm and above**, using A50 and A respectively. The sheet expressly says yield, elongation and hardness entries are **typical for each temper** and its information is **not for purchase specification**. Therefore, even a row printed with “minimum” or “maximum” cannot silently become the contractual acceptance basis. Match the product specification, specimen and certificate. [Aurubis Finland, Pori Cu-DHP sheet](https://www.aurubis.fi/wp-content/uploads/2020/06/Cu_DHP.pdf)

Do not translate an EN rolled-product condition directly into an ASTM tube temper without checking both standards. Cold forming, heating and joining also require assessment against the final required condition.

## Conductivity: preserve the qualification

The Aurubis Stolberg sheet specifies electrical conductivity **at least 46 MS/m / 79% IACS**, explicitly applying to the **soft condition only**. It further says conductivity depends on composition, cold deformation and grain size. These conditions belong beside the number; it is not a universal C12200 value independent of processing. [Aurubis Stolberg, physical properties and conductivity note](https://www.aurubis.com/en/dam/jcr%3A1c92bc25-e000-4851-a265-1ffe873aee8f/PNA%20219_Cu-DHP_C12200-E.N.pdf)

KME's rolled-product sheet, whose actual footer reads **Cu-DHP_10_2020** despite its 2021 filename, gives **typical annealed values at 20 °C** of **47 MS/m, 81% IACS**, and **330 W/(m·K)** thermal conductivity. A typical value and another supplier's qualified lower limit are different data categories. Neither replaces an agreed conductivity test on the delivered product. [KME, C12200 Cu-DHP datasheet](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-DHP_01_2021_e.pdf)

## Forming and joining

KME rates cold forming, soldering, brazing and gas-shielded arc welding favorably, while identifying resistance welding and machining as less suitable. It also identifies resistance to hydrogen embrittlement. These are process-selection indications for its Cu-DHP material, not qualified parameters for every joint, tool or atmosphere. Confirm tooling, joint design, filler/flux system, cleaning and any final-condition changes for the application. [KME, fabrication characteristics](https://www.kme.com/fileadmin/DOWNLOADCENTER/COPPER%20DIVISON/4%20Industrial%20Rolled/3_Datasheets/Datasheets_NEW_2021/Cu-DHP_01_2021_e.pdf)

The CDA handbook requires the **corresponding annealed pressure rating** when drawn tube is joined by brazing or welding. Thus, the incoming hard-tube condition cannot be retained as the pressure-rating basis after a joining process that softens it. Select the complete system's rating from the applicable tube, fitting, joint and temperature requirements rather than choosing the highest published tube number. [CDA, Copper Tube Handbook, pressure-rating notes](https://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf)

## Seamless, welded and service-qualified products differ

ASTM's public **B447-12a(2021)** abstract covers welded copper tube with a longitudinal seam free of filler metal and lists C12200 among the permitted compositions. It distinguishes as-welded, welded-and-annealed, welded-and-cold-drawn and fully finished tempers. Consequently, a chemistry match does not establish whether the ordered product is seamless or welded, or which final condition applies. Use the required product standard and edition explicitly. [ASTM, B447 welded copper tube scope and abstract](https://store.astm.org/b0447-12ar21.html)

Environmental suitability also needs more than a general copper corrosion claim. Aurubis Stolberg specifically lists ammonia, certain halide/cyanide/hydrogen-sulfide environments, oxidizing acids and seawater—especially at high flow—as concerns. Assess actual fluid chemistry, temperature, velocity, contaminants and joint materials; an application list is not approval for arbitrary chemical or marine service. [Aurubis Stolberg, corrosion guidance](https://www.aurubis.com/en/dam/jcr%3A1c92bc25-e000-4851-a265-1ffe873aee8f/PNA%20219_Cu-DHP_C12200-E.N.pdf)

## Purchase and release record

An actionable order states alloy, product standard/edition, form, dimensions and tolerances, final temper, surface/cleanliness requirements, certification and required tests. For tubing, retain manufacturing route and joint-system requirements. For a formed or brazed part, inspect the final geometry and material condition rather than relying only on incoming stock data.

Keep supplier typical values, specification requirements and batch results visibly separate. A C12200 certificate does not by itself establish oxygen-service cleanliness, drinking-water certification, a medical-gas product requirement or a complete pressure-system approval. Verify those requirements on the actual finished product and assembly.

## Related reference

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