What temperature is the cutoff for performing welding on base metal?

The cutoff temperature for performing welding on base metal, as specified by the AWS D1.1 Structural Welding Code, is 32°F. This temperature is critical because welding at or below this threshold can negatively affect the quality of the weld due to the potential for insufficient heat input and the challenges presented by cold metal surfaces. At temperatures below freezing, the base metal can become brittle, which increases the risk of cracking and other defects in the weld joint. Hence, adhering to this temperature guideline is essential to ensure the integrity and performance of the weld under service conditions.

Other temperature choices, such as 40°F, 50°F, and 20°F, do not align with the requirements set forth in the AWS D1.1, thus making them unsuitable for welding operations, as they allow for a greater risk of compromising weld quality. Therefore, 32°F is the accepted minimum temperature for safe and effective welding of base metal.