What is the highest dew point permitted when welding sheet steels using a gas-shielded process?

The correct answer is -40°F, which is the highest dew point permitted when welding sheet steels using a gas-shielded process. The dew point is critical in welding as it indicates the moisture content in the air. If the dew point is too high, it can lead to issues such as hydrogen-induced cracking and increased porosity in the weld.

In a gas-shielded process, maintaining a low dew point ensures that the welding environment remains dry, allowing for better arc stability, effective shielding gas coverage, and overall improved weld quality. This is especially important when working with sheet steels, which are often thin and more susceptible to defects caused by moisture.

Thus, adhering to a dew point of -40°F aligns with best practices for ensuring the integrity of the weld and minimizing potential defects in the final product.