The single crystal blades are provided with {HEAD ~ a root portion} which contains a recess or cavity which conforms closely to {TAIL ~ the disk protrusion} 
The single crystal blades are provided with { HEAD ~ a root portion } which contains a recess or cavity which conforms closely to { TAIL ~ the disk protrusion }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL