Turning tool and turning method

A turning tool, comprising:

• a tool body extending along a tool axis and having a base on a tip of the tool body;
• a cutting insert detachably attached to the base and having a cutting edge;
• and
• a measurement device attached to the tool body and configured to measure a distance from the tool body to an object,
• wherein the measurement device has a first distance sensor which measures a distance to an object located radially outward of the tool axis,
• wherein the tool body has
• a first accommodation hole extending along an axial direction of the tool axis and is located across the tool axis on a side opposite to the cutting edge of the cutting insert, and
• an opening hole extending radially outward of the tool axis from the first accommodation hole and opening on an outer peripheral surface of the tool body,
• wherein the opening hole opens across the tool axis toward the side opposite to the cutting edge of the cutting insert,
• wherein the first distance sensor is accommodated in the first accommodation hole,
• wherein a detector of the first distance sensor is exposed radially outward from the opening hole, and
• wherein an axial position of the tool axis of a measurement point measured by the first distance sensor overlaps an axial position of the cutting insert, and the measurement point is located across the tool axis on the side opposite to the cutting edge of the cutting insert.