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