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