For effective transporting away of chips, {HEAD ~ the main flute} and the reamer flutes preferably have {TAIL ~ the same helix orientation} 
have
For effective transporting away of chips , { HEAD ~ the main flute } and the reamer flutes preferably have { TAIL ~ the same helix orientation }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL