The free lengths of {TAIL ~ the finished springs} may be controlled by applying {HEAD ~ axial forces} during heat hardening 
The free lengths of { TAIL ~ the finished springs } may be controlled by applying { HEAD ~ axial forces } during heat hardening
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH