C11000 vs. C12200: Which copper sheet is right for welding?

For industrial applications involving high-temperature brazing or welding, C12200 (DHP) is the technically superior copper sheet. While C11000 (ETP) offers the highest electrical conductivity at 101% IACS min, its internal oxygen content makes it susceptible to hydrogen embrittlement and cracking during the welding process. C12200, which is phosphorus-deoxidized, eliminates this risk and ensures structurally sound joints for chemical tanks, solar absorbers, and heat exchanger plates. You can evaluate our available stock dimensions for industrial projects on the C11000 sheet.

The fundamental difference between these two grades lies in how they are refined. C11000 copper contains a controlled amount of oxygen (0.02% to 0.04%), which is beneficial for electrical conductivity but fatal during welding. When exposed to a hydrogen-rich welding flame, this oxygen reacts to form internal steam pockets that destroy the metal's integrity. As discussed in our report on whether is C11000 copper oxygen free, this is the primary reason engineers switch to deoxidized grades.

C12200 is refined by adding approximately 0.015% to 0.040% phosphorus. This phosphorus "scavenges" the oxygen, creating a material that is completely safe for all joining processes. However, this addition drops the conductivity to roughly 85% IACS. If your application is strictly for power transmission, you should stick with the chemical composition of C11000 alloy found in ETP copper.

C11000 vs. C12200 Sheet Material Properties

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The decision is usually based on the "Joining Method." If your industrial assembly uses mechanical fasteners (bolts/rivets) or low-temperature soldering, c11000 material is the better investment because it moves heat and electricity more efficiently. It is the global standard for C11000 plate used in electrical grounding and high-performance heatsinks.

However, if the plate must be TIG or MIG welded into a pressurized vessel or a solar thermal collector, C12200 is mandatory. While the t2 copper provides better thermal speed, a leaking weld in a heat exchanger is a catastrophic failure that far outweighs the 15% difference in thermal conductivity.

Fabrication and Joining Ratings

From a procurement standpoint, the C11000 copper price is the baseline for the entire copper industry. Because C11000 is produced in massive electrolytic refineries, it is generally the most cost-effective pure copper grade. C12200 often carries a small premium due to the additional phosphorus deoxidation step and its status as a specialized industrial alloy.

For architectural roofing, both grades are used. However, C12200 is often preferred for large, welded gutters and downspouts, while C11000 is standard for the main shingles and flashing where no structural welding is required.

1. Why is C12200 called "DHP" copper?
DHP stands for Deoxidized High Phosphorus. It indicates that the material has been treated with phosphorus to remove oxygen, making it safe for welding.

2. Is C11000 considered "Pure Copper" even with oxygen?
Yes. Since it maintains a 99.90% minimum copper content (including silver), it is classified as commercially pure copper. The oxygen is considered a necessary part of the "Tough Pitch" refining process.

3. Which grade has better corrosion resistance for roofing?
C12200 is generally considered slightly more resistant to "pitting" corrosion in water-handling applications, but both grades will develop a protective green patina over time.

4. What is the equivalent of C12200 in international standards?
The most common equivalent is Cu-DHP (CW024A) in European standards (EN). It is the standard material for industrial copper piping and heat exchanger plates.

5. Can I use C11000 for a solar absorber plate?
Yes, provided the tubes are joined via mechanical expansion or ultrasonic welding. If you plan to braze the tubes to the plate using a torch, C12200 is a safer choice for the assembly.

6. Do you supply custom-cut plates in both grades?
Yes. we maintain large inventories of C11000 for electrical applications and C12200 for industrial fabrication. We can provide precision shearing and water-jet cutting to meet your specific blueprint requirements.

Customization Note:

Custom Dimensions: We provide precision cutting and slitting services to meet your specific project requirements.

Tempers Available: Soft (O), Half-Hard (H02), Full Hard (H04), and Spring Hard (H08).

Surface Finish: Bright annealing, Polished, or Plated (Tin, Silver, Nickel) upon request.

Maximum protection against oxidation, moisture, and transit damage.

1. Anti-Oxidation Protection

VCI Paper & Moisture-Proof Film: Every order is vacuum-sealed or wrapped in anti-corrosion materials to ensure the copper remains bright and tarnish-free during sea freight.

2. Reinforced Structural Support

Seaworthy Wooden Crates: We use reinforced, fumigation-free wooden cases (ISPM-15) and steel strapping for rods, tubes, and heavy plates to prevent bending or surface scratches.

3. Secure Handling & Loading

Forklift-Ready Pallets: All materials are secured on standardized export pallets for easy unloading and maximum stability in containers.

4. Clear Identification

Professional Labeling: Each package includes detailed labels with heat numbers, specifications, and net weight for efficient inventory management.

1. Core Production Equipment

Up-casting & Continuous Casting Lines: Ensures high-purity oxygen-free copper rods and wires with uniform grain structure.

High-Precision Cold/Hot Rolling Mills: Automated thickness control for copper plates and strips with tolerances within ±0.01mm.

Large-Scale Extrusion & Drawing Machines: Capable of producing seamless copper tubes and rods in diverse diameters and shapes.

Atmospheric Controlled Annealing Furnaces: Bright annealing process to achieve specific tempers (Soft, Half-hard, Hard) without surface oxidation.

2. In-House Testing Center

Direct-Reading Spectrometers: Instant chemical composition analysis to guarantee Cu purity and precise alloying (Brass, Bronze, etc.).

Universal Tensile Testers: Verifying mechanical properties including tensile strength, elongation, and yield strength.

Eddy Current & Ultrasonic Testing: 100% non-destructive inspection for tubes and rods to detect internal cracks or flaws.

Conductivity & Hardness Testers: Ensuring electrical conductivity (IACS) and Vickers/Rockwell hardness meet international standards (ASTM, EN, DIN).

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