What is the minimum length of an intermittent fillet weld?

The minimum length of an intermittent fillet weld is indeed specified in the AWS D1.1 Structural Welding Code – Steel. The code dictates that the length of any single segment of an intermittent fillet weld should be at least 1.5 inches (1-1/2"). This requirement ensures that the welds can provide sufficient strength and performance under load, mitigating the risks associated with under-welding. Intermittent fillet welds are typically used to reduce the amount of weld metal and, consequently, distortion, while still maintaining adequate joint performance.

Choosing a length of 1.5 inches aligns with structural integrity principles, allowing for appropriate distribution of stress and improving the overall reliability of the welded joint. Other lengths suggested may not meet the codified minimum requirement, which is critical for ensuring that welds can effectively perform their intended role in structural applications.