Patent ID: 9604286
Date: 2017-03-28
CPC Classifications: B23B,Y10T

Claim:
1. A drill with a cutting fluid supply hole comprising: a tool main body provided with a cutting edge that is located at an axial end thereof, a flute portion having a discharge flute formed on a distal end side portion of the tool main body for discharging chips generated by the cutting edge, and a cutting fluid supply hole for supplying cutting fluid toward the cutting edge through the inside of the flute portion, the cutting fluid supply hole having a fan-shaped cross section defined by a front inner wall surface extending along a radial direction of the tool main body on the front side in the rotation direction of the drill, a rear inner wall surface extending along the radial direction on the rear side in the rotation direction of the drill and facing the front inner wall surface in a circumferential direction of the tool main body, an outer circumferential inner wall surface made up of a partially cylindrical surface around a center line of the drill, and an inner circumferential inner wall surface made up of a partially cylindrical surface around the center line of the drill with a curvature radius that is smaller than a curvature radius of the outer circumferential inner wall surface and facing the outer circumferential inner wall surface in the radial direction.