{HEAD ~ the first diameter} of {TAIL ~ said first parallel thread part} is substantially 3.55 mm; and 
of
{ HEAD ~ the first diameter } of { TAIL ~ said first parallel thread part } is substantially 3.55 mm ; and
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH