In fact, {TAIL ~ the holes} 50 can be formed with threads to receive {HEAD ~ the inserts} 
In fact , { TAIL ~ the holes } 50 can be formed with threads to receive { HEAD ~ the inserts }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD