In material 5â„8 in or less thick, the thickness of plug or slot welds should be the same as the material thickness. In material more than 5â„8 in thick, the weld thickness should be at least half the material thickness but not less than 5â„8 in.
Diameter of hole for a plug weld should be at least the depth of hole plus 5â„16 in, but the diameter should not exceed minimum diameter 1â„8 in, or 21â„4 times the thickness of the weld metal, whichever is greater.
Slot welds may be spaced no closer than four times their width in a direction transverse to the slot length. In the longitudinal direction, center-to-center spacing should be at least twice the slot length.