TY JOUR TI Hole accuracy increase at hole reaming in hard-to-machine parts KW reaming KW reamer geometry KW hole accuracy KW ultra-sonic oscillations KW hard-to-machine materials JO Science intensive technologies in mechanical engineering AU Agapov, S.I. AU Sidyakin, Y.I. AU Korpelyansky, O.F. PY 2018 IS 2018 PB Bryansk State Technical University