What is the minimum depth of filling for plug or slot welds greater than 5/8"?

The minimum depth of filling for plug or slot welds that are greater than 5/8" is specified as either 50% of the thickness of the metal or 5/8”, whichever is larger. This requirement ensures that the weld effectively contributes to the structural integrity of the assembly by providing adequate fusion and strength.

By allowing for a depth of 50% of the thickness of the metal, the code accommodates variations in material thickness, ensuring that even thicker materials receive sufficient weld penetration. The additional stipulation of 5/8" as a minimum depth ensures that for thinner materials, there is still a robust and effective weld that meets the design strength criteria.

This approach reflects the design principles in welding, where weld strength and reliability depend not only on proper technique but also on adequate material fusion. Therefore, using this criterion helps maintain structural integrity and ensures safety across different scenarios.