Various other keying means could be used to affix {HEAD ~ the disc} 51 to {TAIL ~ the shaft} 
to
Various other keying means could be used to affix { HEAD ~ the disc } 51 to { TAIL ~ the shaft }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL