Copper and its alloys remain indispensable in modern industry due to their exceptional electrical and thermal conductivity, corrosion resistance, and workability. Among the numerous copper grades, C11000 (ETP Copper), C12000 (DLP Copper), and C12200 (DHP Copper) are three of the most widely specified. Understanding their distinct properties, governed primarily by their oxygen and phosphorus content, is crucial for optimal material selection in design and manufacturing.
Fundamental Classification and Composition
C11000 (Electrolytic Tough Pitch Copper - ETP): This is the standard, non-deoxidized industrial pure copper. It contains a controlled amount of oxygen (0.02%-0.04%) which exists as copper oxide (Cu₂O) within the microstructure. It has no deliberate phosphorus addition.
C12000 (Deoxidized Low-Phosphorus Copper - DLP): This is a deoxidized copper where a small, precise amount of phosphorus (0.004%-0.012%) is added to scavenge oxygen, forming phosphorus pentoxide (P₂O₅) which volatilizes. This results in a very low residual oxygen and phosphorus content.
C12200 (Deoxidized High-Phosphorus Copper - DHP): This is also a phosphorus-deoxidized copper, but with a intentionally higher residual phosphorus content (0.015%-0.040%). The higher phosphorus level ensures complete deoxidation and imparts specific beneficial properties.
Property Comparison
| Property | C11000 (ETP) | C12000 (DLP) | C12200 (DHP) | Technical Implication |
|---|---|---|---|---|
| Electrical Conductivity | Excellent (≥101% IACS) | Very High (≥98% IACS) | Good (≥85% IACS) | C11000 is the benchmark for conductivity. C12000 retains near-pure conductivity, while C12200's is reduced by phosphorus scattering electrons. |
| Thermal Conductivity | Excellent (~390-400 W/m·K) | Very High (~340-380 W/m·K) | Good (~250-340 W/m·K) | Follows a similar trend to electrical conductivity. Critical for heat sink and heat exchanger efficiency. |
| Weldability & Brazability | Poor for fusion welding in reducing atmospheres. Risk of Hydrogen Embrittlement. | Excellent. Immune to hydrogen embrittlement. Good for all welding/brazing. | Superior. Excellent brazability; phosphorus can act as a self-fluxing agent. | The presence of Cu₂O in C11000 reacts with hydrogen (e.g., from flame welding) causing micro-cracks. Deoxidized grades (C12xxx) are safe. |
| Hot Workability | Fair to Good. Can be brittle at high temps. | Very Good. | Excellent. Phosphorus significantly improves hot ductility. | C12200 is the preferred choice for hot extrusion, forging, and rolling complex shapes. |
| Corrosion Resistance | Good in standard atmospheres. | Very Good. Better high-temp oxidation resistance than C11000. | Excellent. Superior resistance to scaling, erosion-corrosion, and dezincification. | Higher phosphorus enhances the formation of more stable, protective surface films. |
| Key Design Strength | Maximum Electrical/Thermal Conductivity | Optimal Balance: High Conductivity + Fabricability | Maximum Fabricability & Brazability | C12000 is the "best compromise" alloy. |
| Fatal Flaw / Limitation | Susceptible to Hydrogen Embrittlement. | Slightly lower conductivity than C11000. | Lowest conductivity of the three. | Dictates the application boundary. |
Application-Based Selection Guidelines
Choose C11000 (ETP Copper) when:
Absolute maximum electrical or thermal conductivity is the non-negotiable #1 priority.
Application Examples:
Electrical busbars, power transmission cables, and transformer windings.
Non-welded, high-current electrical contacts and connectors.
Waveguides and other RF components where signal loss must be minimized.
Decorative applications where bright annealed finish is desired (and will not be welded).
Choose C12000 (DLP Copper) when:
You require high conductivity AND reliable weldability/brazability.
You need a safely deoxidized copper for critical pressure systems.
Application Examples:
Welded or brazed heat exchangers and condenser tubes (where efficiency matters).
Medical gas piping (ASTM B819) and refrigeration tubing.
Vacuum system components and electronic package headers.
Electrical components that must be soldered or welded without risk of embrittlement.
Choose C12200 (DHP Copper) when:
Ease of fabrication, superior brazability, and corrosion resistance are more important than top-tier conductivity.
Application Examples:
Plumbing tube, fittings, and valves for potable water systems.
HVAC/R (Air Conditioning & Refrigeration) tubing (ACR tube).
Architectural roofing, flashing, and gutters.
General sheet metal work, tanks, and process vessels.
The selection between C11000, C12000, and C12200 beautifully illustrates a fundamental metallurgical trade-off. Phosphorus is the key variable. Its addition transforms the material:
From C11000 to C12000: Adding a tiny amount of phosphorus (~0.01%) sacrifices less than 3% conductivity but completely eliminates the risk of hydrogen embrittlement, enabling safe welding and improving hot workability. This is often an excellent trade.
From C12000 to C12200: Adding more phosphorus (up to ~0.04%) further enhances fabrication, brazing, and corrosion properties but reduces conductivity by 15-20%. This is the choice when conductivity is a secondary concern to manufacturability and durability.
Our product range
| Category | Key Products | Standards | Typical Applications |
|---|---|---|---|
| Copper Tubes & Pipes | Seamless copper tubes, medical gas pipes (ASTM B819), ACR tubes, capillary tubes, large-diameter pipes, plumbing tubes (Type K/L/M) | ASTM B68, B75, B88, B280, B819, EN1057 | HVAC, refrigeration, plumbing, medical gas systems, industrial pipelines |
| Copper Sheets & Plates | Pure copper sheets, copper alloy plates (brass, bronze), perforated sheets, embossed sheets, clad sheets | ASTM B152, B465, EN1652 | Architectural cladding, electrical components, heat exchangers, decorative arts |
| Copper Bars & Rods | Round bars, square bars, hexagonal bars, flat bars, copper alloy rods (brass, bronze) | ASTM B187, B301, EN12163/12164 | Machined parts, connectors, fasteners, electrodes, forgings |
| Copper Wires & Strands | Bare copper wires, tinned copper wires, braided wires, stranded conductors, enameled wires | ASTM B1, B3, B174, IEC 60228 | Electrical wiring, power transmission, cables, windings, grounding systems |
| Copper Foils | Rolled copper foils, electrolytic copper foils, flexible copper strips | ASTM B370, IPC-4562 | Printed circuit boards (PCBs), electromagnetic shielding, batteries, decorative laminates |
Our factory
Our factory is equipped with state-of-the-art production lines for extrusion, rolling, drawing, and finishing. We specialize in producing a full range of copper and copper alloy products, including tubes, plates, bars, wires, and foils, serving the global HVAC, construction, electrical, medical, and automotive industries.
We are committed to quality and precision, strictly adhering to international standards including ASTM, EN, DIN, and JIS, and maintaining ISO 9001 certification. Our in-house laboratories conduct rigorous testing-from chemical composition and mechanical properties to pressure and cleanliness verification-ensuring end-to-end traceability and compliance for our products.
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