When is a 5/8" depth of filling required for plugs or slot welds?

A 5/8" depth of filling is required for plugs or slot welds specifically when the base metal thickness exceeds 5/8". This requirement is outlined to ensure adequate fusion and strength in the weld, as a weld that is too shallow may not provide sufficient weld penetration and therefore may compromise the structural integrity of the joint.

When the metal thickness is greater than 5/8", achieving a weld depth of 5/8" allows for better distribution of stresses across the joint and a stronger connection. It ensures that the weld metal fills the void completely, allowing for the necessary mechanical properties to be developed within the welded connection.

In contrast, for base metals that are 1" thick or 3/8" thick, the required weld depth would differ based on specific guidelines in the AWS D1.1 code, which means those choices do not align with this particular requirement for weld depth. The code provides parameters that reflect the needed depth of welds based on the specifics of the material being joined, ensuring safe and reliable structural connections.