Which polarity would provide deeper penetration?

Which polarity would provide deeper penetration?

• A. Reverse polarity
• B. Straight polarity
• C. AC
• D. DC negative

Answer: (A)

Polarity in arc welding determines where most of the heat goes. When you use reverse polarity, the electrode is positive and the workpiece is negative, which tends to push more heat into the base metal. That added heat into the joint allows the weld pool to fuse deeper into the parent metal, giving greater penetration. In contrast, straight polarity concentrates heat at the electrode, so the weld tends to sit more on or near the surface with less penetration. AC switches polarity constantly, so penetration isn’t as consistently deep as with steady reverse polarity. So, to achieve deeper penetration, reverse polarity is the choice.

Polarity in arc welding determines where most of the heat goes. When you use reverse polarity, the electrode is positive and the workpiece is negative, which tends to push more heat into the base metal. That added heat into the joint allows the weld pool to fuse deeper into the parent metal, giving greater penetration. In contrast, straight polarity concentrates heat at the electrode, so the weld tends to sit more on or near the surface with less penetration. AC switches polarity constantly, so penetration isn’t as consistently deep as with steady reverse polarity. So, to achieve deeper penetration, reverse polarity is the choice.