What is the maximum diameter of porosity allowed in any 4 inches of fillet weld?

In the context of welding standards, specifically the requirements set forth by organizations such as the American Welding Society (AWS) or the International Code Council (ICC), the maximum diameter of porosity allowed in a fillet weld is crucial for ensuring the structural integrity of the weld joint.

A porosity size of 3/32" is the maximum that can be accepted within a length of 4 inches of fillet weld. This limit is established to minimize the potential for weld defects that could compromise the mechanical properties and longevity of the welded structure. It reflects industry standards aimed at ensuring that the welds maintain sufficient strength and are free of significant defects that could lead to premature failure in structural applications.

In contrast, larger sizes of porosity would not meet the stringent criteria set for acceptable weld quality, which seeks to ensure the reliability and safety of welds used in construction. Such larger porosity could indicate issues in the welding process, such as contamination or improper technique, and therefore would not be deemed acceptable in a certified weld.