Which metals are typically welded with straight polarity?

The correct response highlights that thinner metals are typically welded with straight polarity in Shielded Metal Arc Welding (SMAW). When using straight polarity (also known as DCEN - direct current electrode negative), the majority of the electrical current flows through the electrode to the workpiece. This setup provides deeper penetration, which is particularly advantageous when working with thinner materials, as it minimizes the risk of burn-through while still effectively fusing the metal.

In contrast, thicker metals often require a different approach, such as using reverse polarity (DCEP - direct current electrode positive), which can provide a wider arc and increased heat for better fusion. Non-ferrous metals may also require specialized techniques and filler materials, which could include different polarity settings depending on the specific characteristics of the metal being welded. The option suggesting that all types of metals can be welded with straight polarity does not consider these nuances and specific requirements associated with different material thicknesses and types.