| RWMA Class | UNS No. | Description and Primary Uses |
| 1 | C15000 | A copper zirconium material recommended for spot welding coated materials and highly conductive materials such as aluminum, magnesium alloys, brass and bronze. |
| 2 | C18200 | A copper, chromium material recommend for high production operations spot welding hot or cold rolled steels, galvanized and coated materials. |
| 2 | C18150 | A copper, chromium, zirconium material recommend for spot welding hot or cold rolled steels, galvanized and coated materials. The chromium increases the creep resistance compared to the other Class 2 Alloy (C18200) making it an ideal choice for automated environment with high production rates. |
| 3 | C18000 | A beryllium free resistance welding alloy recommended for spot welding high resistance materials such as stainless steel, Nichrome, Inconel and Monel. Although the conductivity is slightly less than the C17510 alloy, the C18000 alloy is a suitable cost effective substitute for C17510 alloy. |
| 3 | C17510 | A copper, beryllium resistance welding alloy recommended for spot welding high resistance materials such as stainless steel, Nichrome, Inconel and Monel. |
