What Exactly Is A Plug Weld & What Is It Good For?

Slot welds are stronger than plug welds but require more filler metal A small weld made on or between the surfaces of overlapping parts Multiple spot welds

To enable thicker plate to be joined by 'spot welding' a circular or elongated hole may be machined through the top plate, enabling either a plug or a slot weld

plug slot Plug welds and slot welds are identified by the same symbol, except that the plug weld symbol has a diameter symbol placed on its right side

plug weld vs slot weld 3 Qualification of any groove weld or fillet weld procedure, qualifies any WPS for making plug and slot welds 6 Welders qualified to make