CUTTING TOOL AND CUTTING INSERT FOR THREAD WHIRLING

The present invention relates to a cutting tool and a cutting insert for thread whirling. In the cutting tool for thread whirling, when the cutting edge of the cutting insert is re-ground on the rakeface side and the insert is fixed to the tool body, the exchange operation can be performed without adjusting the position of a tool nose again. The cutting insert is formed into a plate shape of an isosceles trapezoid, the inner angle between the lower bottom and each waist is used as a tool corner, a cutting edge having a rake face at an end of the lower bottom is also included, and the clampingportion of the tool body includes: a first constraining wall surface that constrains the rake face side surface of the insert as a first constrained surface; and a second constraining wall surface that constrains the minor flank side surface of the insert as a second constrained surface. By pressing the first constrained surface to the first constraining wall surface and pressing the second constrained surface to the seco