Joint dimension in Table UW-12

[mrsteam]

Table UW-12, for type (4) joint, specifies that Category C circumferential joints should not be over 5/8" thick. Is this refering to the weld leg / collar dimension of the fillet weld? Or to the thickness of the components being welded together? If neither, what does it refer to?

Thank you very much for your valuable insight

 

[unclesyd]

Unless things have changed it is referring to thickness of the components being joined.