Technical Specifications
Conductivity
≥75% IACS
Hardness
≥75 HRB
Temperature
475°C
Standard
AWS J1.3
Properties Table (AWS J1.3)
| Property | Value | Unit |
|---|---|---|
| RWMA Class | Class 2 | - |
| UNS Code | C18150 | - |
| Composition | Cu + 0.5-1.5% Cr + 0.02-0.20% Zr | % wt |
| Electrical Conductivity | ≥80 | % IACS |
| Hardness | ≥75 | HRB |
| Thermal Conductivity | 330 | W/m·K |
| Softening Temperature | 475 | °C |
| Density | 8.89 | g/cm³ |
What Does Zirconium Add?
C18150 (CuCrZr) is a variant of the standard Class 2 (C18200) with added zirconium. The zirconium improves the synergy between copper and chromium in the alloy:
- Better alloy bonding - zirconium improves how copper and chromium integrate
- Slightly better properties in theory compared to C18200
- Same RWMA Class 2 - meets the same AWS J1.3 specifications
- In practice - the difference with C18200 is minimal, they are very similar
Applications
C18150 is used in the same applications as C18200:
- Automotive welding - body panels, structures
- Low carbon steels - general applications
- Galvanized steels - same as C18200
- High volume production - OEM and Tier 1 lines
In practice, C18150 and C18200 are interchangeable for most Class 2 applications.
C18150 vs C18200: Both are RWMA Class 2 with very similar properties. The practical difference is minimal - zirconium slightly improves alloy quality. For applications requiring higher hardness (AHSS/UHSS), consider Class 3 (CuNiBe - C17510).
When to Consider Another Option
C18150 and C18200 are very similar in practice. Consider the following:
- C18200 available: If you have access to C18200 and it works well, there's no need to switch to C18150. They're practically interchangeable.
- AHSS/UHSS steels: If you need higher hardness and wear resistance, Class 2 (either C18200 or C18150) may not be enough. Consider Class 3 (90 HRB vs 75 HRB).
- Higher conductivity: If you need maximum conductivity and less current, Class 1 (C15000) may be a better option.
In summary: C18150 is a good option if available, but C18200 works just as well for most applications.
What We See in Real Applications
In our experience:
- They're interchangeable: Most plants use C18200 or C18150 interchangeably for Class 2 applications.
- Same process: Even in manufacturing, they're sometimes processed similarly - the practical difference is minimal.
- The right class matters more: The most important decision is choosing the right class (1, 2, 3, etc.) for your application, not so much the specific variant within Class 2.
If you have questions about which Class you need, we're happy to help evaluate your application.