Which of the following statements is true about E6010 electrodes?

• A. They provide deep penetration and require DC reverse polarity only
• B. They provide shallow penetration and require AC
• C. They provide moderate penetration and require DC straight polarity
• D. They do not require any polarity specification

Answer: (A)

E6010 electrodes are designed for deep penetration when welded with direct current in reverse polarity. The cellulose-sodium coating creates an arc that heats the base metal aggressively, giving a weld with substantial depth, which is ideal for root passes and welding in less-than-perfect surfaces. To achieve that depth and arc stability, you run with DC positive on the electrode (reverse polarity). Using alternating current or DC straight polarity reduces penetration and arc control, so those setups aren’t correct for this electrode. The polarity specification matters for how the arc behaves, so saying there’s no polarity requirement isn’t accurate.