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