In {TAIL ~ one threading tool}, {HEAD ~ the insert cross section} forms substantially a hexagon with two opposite sides longer than the other four sides  
In
In { TAIL ~ one threading tool } , { HEAD ~ the insert cross section } forms substantially a hexagon with two opposite sides longer than the other four sides
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH