The drive element engages the top of {HEAD ~ the foremost fastener} of {TAIL ~ the strip} of fasteners to force the fastener into a work piece 
of
The drive element engages the top of { HEAD ~ the foremost fastener } of { TAIL ~ the strip } of fasteners to force the fastener into a work piece
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH