C18200 Class 2 Chromium Copper (RWMA Class 2)
C18200 is a high-performance chromium copper alloy classified as RWMA Class 2 copper. It offers a balance of high electrical conductivity, exceptional mechanical properties, and strong wear resistance. This class 2 copper alloy is engineered for applications requiring thermal conductivity and strength at elevated temperatures, most notably in resistance welding electrodes, electrical and thermal conductors, and various high-load components.
Its reliable performance under heat and electrical stress makes C18200 copper ideal for seam welding wheels, spot welding tips, electrode holders, flash welding electrodes, and butt weld fair capacity applications in demanding environments. It also performs well in thermal conductors requiring greater strength and efficiency at high temperatures.
Other industrial uses include heat sinks, cable connectors, heat-treated wear plates, and current-carrying structural members.
What is C18200 Chromium Copper?
C18200 is a chromium copper alloy containing approximately 1% chromium and 99% copper. With that small addition of chromium, C18200’s strength, hardness, and heat resistance is improved while preserving conductivity.
As an RWMA Class 2 alloy, C18200 is widely used in resistance welding applications due to its ability to:
- Resist deformation under high heat
- Maintain consistent electrical and thermal performance
- Provide a longer service life than pure copper electrodes
Key Properties of C18200 Class 2 Copper
Minimum Physical Properties
Diameter – Round Stock (Cold Worked)
| Size Range in MM | Size Range in MM | Hardness Rockwell | Conductivity % I.A.C.S. | Yield Strength KSI (typical) | Ultimate Tensile Strength (typical) | Elongation % *(typical) |
| Up to 1″ | Up to 22 | 75 HRB | 75% | 55 | 65 | 13% |
| Over 1″ to 2″ | Over 25 to 51 | 70 HRB | 75% | 55 | 59 | 13% |
| Over 2″ to 3″ | Over 51 to 76 | 65 HRB | 75% | 55 | 55 | 13% |
Thickness – Square, Rectangle, and Hexagonal Bar Stock (Cold Worked)
| Size Range in MM | Size Range in MM | Hardness Rockwell | Conductivity % I.A.C.S. | Yield Strength KSI (typical) | Ultimate Tensile Strength (typical) | Elongation % *(typical) |
| Up to 1″ | Up to 25 | 70 HRB | 75% | 45 | 65 | 13% |
| Over 1″ | Over 25 | 65 HRB | 75% | 40 | 55 | 13% |
Thickness – Forgings
| Size Range in MM | Size Range in MM | Hardness Rockwell | Conductivity % I.A.C.S. | Yield Strength KSI (typical) | Ultimate Tensile Strength (typical) | Elongation % *(typical) |
| Up to 1″ | Up to 25 | 65 HRB | 75% | 45 | 55 | 13% |
| Over 1″ to 2″ | Over 25 to 51 | 65 HRB | 75% | 45 | 55 | 13% |
| Over 2″ | Over 51 | 65 HRB | 75% | 40 | 55 | 13% |
Chemical Composition
| Cu | Cr | Fe | Pb | Si |
| Rem. | .6-1.2 | .10 max | .05 max | .10 |
Applications of C18200 Chromium Copper
Resistance Welding Applications
- Spot Welding Electrodes: C18200 maintains shape and conductivity across thousands of weld cycles, making it suitable for cap-style and projection welding electrodes.
- Backup Electrodes and Shunts: C18200 provides the necessary hardness and thermal resistance to help these components support or redirect current during welding.
- Electrode Holders and Adaptors: C18200 ensures efficient current transfer in automated and manual welding setups.
- Flash and Butt Welding Dies: In flash and butt welding, dies are subjected to intense, sustained heat. C18200 resists deformation and delivers reliable performance during continuous-duty operations.
Industrial & Automotive
- Welding Arms, Shanks, and Platens: C18200 is used to manufacture arms, shanks, and platens carrying high current while withstanding repeated thermal cycling and mechanical pressure.
- High-Wear Tooling Components: Welders and metal workers find regular use for C18200 in tooling components that experience repeated impact, friction, or thermal stress, such as inserts, dies, and clamps. It demonstrates a high resistance to softening and surface wear. These properties make it a reliable choice in high-throughput industrial operations where frequent tool replacement would disrupt production or affect dimensional accuracy.
- Aerospace and Automotive Welding Fixtures: This high-conductivity copper alloy is used in welding fixtures that support or position parts during high-temperature joining processes. Its combination of strength, conductivity, and wear resistance ensures long fixture life and consistent part placement, even under repeated thermal and mechanical load.
Why Choose NSRW for C18200 Copper?
Here at NSRW we are a trusted partner for industries that rely on Class 2 copper alloys, while also offering precision fabrication and technical support. Here’s why our customers choose us:
- Extensive stock of C18200 bars, plates, and rods
- Custom fabrication for electrodes, bus bars, and connectors
- Engineering expertise in resistance welding applications
- Nationwide distribution for fast lead times and reliable supply
If you’re searching for C18200 copper suppliers, NSRW provides the expertise and inventory to meet your needs.
Request a Quote for C18200 Copper
Looking to buy C18200 copper chromium material or related high-strength copper alloy components? Our team can guide you through material selection, fabrication options, and pricing, whether you’re fabricating switch contacts, generator components, or electrical connectors. Contact NSRW today to receive a quote or speak with an expert about your needs.
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