Some states don't allow safety chains to be welded.
Here is the first one I found:
: Texas Administrative Code
4) Safety chains must be attached to either side of the tongue or connecting apparatus of the towed vehicle, equidistant forward and aft of the hitch or connector. They shall not be directly welded to the towed vehicle, but rather shall be connected by means of bolts, pins, or other secure connecting methods, that meet necessary strength requirements.
Here is the first one I found:
: Texas Administrative Code
4) Safety chains must be attached to either side of the tongue or connecting apparatus of the towed vehicle, equidistant forward and aft of the hitch or connector. They shall not be directly welded to the towed vehicle, but rather shall be connected by means of bolts, pins, or other secure connecting methods, that meet necessary strength requirements.