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