The sheets, prior to welding, are first spot welded, wherein they are clamped only during this spot welding in order to ensure {HEAD ~ the maintenance} of {TAIL ~ a maximum gap width} 
of
The sheets , prior to welding , are first spot welded , wherein they are clamped only during this spot welding in order to ensure { HEAD ~ the maintenance } of { TAIL ~ a maximum gap width }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL