PURPOSE: To favorably machine a workpiece by providing internal teeth of a tool with a range where dynamically acting tooth trace correction for finishing honing work is not conducted, or where only slight dyamically acting tooth trace correction is conducted, and a range where large dynamically acting tooth trace correction for honing work is conducted.

CONSTITUTION: A tool is placed stationary, a pitch surface of a workpiece or a finishing wheel is moved relatively to the tool along the tool, and the pitch surface of the workpiece or finishing wheel is indicated at four contact positions 1, 2, 3, 4. In addition, a contact condition is simplified, and extremely enlarged to be indicated as a flat cross section. A tool pitch surface TV having a dynamically acting small crowning radius RKv is used for prehoning. A tool pitch surface TF having a dynamically acting large crowning radius RKF is used for finishing honing. Prehoning work and finishing work can thus be conducted using the single tool.