Which electrode last number consistently operates on Direct Current Negative?

The electrode with the last number "2" indicates that it consistently operates on Direct Current Negative (DCN). In the context of welding, particularly with the AWS classification system, the last digit of an electrode number is crucial for determining its polarity compatibility.

Electrodes that end in "1" or "0" typically operate with Alternating Current (AC) or Direct Current Positive (DCP), while those that end with "2" are designed for use with Direct Current Negative. This polarity configuration is essential, as it affects the arc stability and heat distribution during the welding process. The DCN polarity provides deeper penetration into the workpiece and is ideal for specific applications and materials.

Understanding these classifications is critical for welders to select the appropriate electrode for their specific welding tasks, ensuring not only the quality of the weld but also the efficiency and effectiveness of the process.