The 8 in the designation E71T-8 indicates?

In the designation E71T-8, the "8" pertains to the specific type of shielding gas used in the welding process. Specifically, it indicates that the filler metal can be used with a DC (direct current) negative polarity when using a carbon dioxide shielding gas. This detail is crucial for welders as it affects the arc stability, penetration, and overall quality of the weld.

The designation itself helps in identifying both the intended application and the performance characteristics of the filler metal. The number represents specific mechanical properties and classifications established by the American Welding Society (AWS), which aids welders in choosing the right electrode for different types of welding jobs.

By understanding that the "8" signifies the requirement for DC negative polarity, welders can ensure they set up their equipment correctly and use the appropriate shielding gas to achieve desired results. This understanding directly ties to the quality and integrity of the welds they produce, making it critical knowledge for anyone in the field.