# US 2025/0083237 A1 · Drill > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0083237 A1 - Document ID: US20250083237A1 - Status: Published application - Kind: A1 - Application number: 18/288,383 - Filed: 2023-01-12 - Published: 2025-03-13 - Earliest claimed: 2023-01-12 - Assignees: Sumitomo Electric Hardmetal Corp. - Applicants: Sumitomo Electric Hardmetal Corp. - Inventors: Koji TAKAHASHI - Web page: https://patentgrep.com/patent/US20250083237A1 ## CPC - B23B 51/02: Twist drills - B23B 2251/04: Angles, e.g. cutting angles - B23B 2251/14: Configuration of the cutting part, i.e. the main cutting edges - B23B 2251/182: Web thinning - B23B: TURNING; BORING (arrangements for copying or controlling B23Q) ## Abstract A first flank face includes a first front flank face portion and a first rear flank face portion. A second flank face includes a second front flank face portion and a second rear flank face portion. A ridgeline between the first front flank face portion and the first rear flank face portion is defined as a first ridgeline. A ridgeline between the second front flank face portion and the second rear flank face portion is defined as a second ridgeline. When viewed in the axial direction, a distance between the first ridgeline and the second ridgeline in a direction perpendicular to the first ridgeline is greater than 0 mm and less than or equal to 0.03 mm. ## Claims ### Claim 1 A drill that rotates around an axis, the drill comprising: a first flank face; a first thinning face provided rearwardly of the first flank face in a rotation direction; a second flank face provided rearwardly of the first thinning face in the rotation direction; and a second thinning face provided rearwardly of the second flank face in the rotation direction, wherein the first flank face includes a first front flank face portion, and a first rear flank face portion that is contiguous to the first front flank face portion, is inclined with respect to the first front flank face portion, and is provided rearwardly of the first front flank face portion in the rotation direction, the second flank face includes a second front flank face portion, and a second rear flank face portion that is contiguous to the second front flank face portion, is inclined with respect to the second front flank face portion, and is provided rearwardly of the second front flank face portion in the rotation direction, the second front flank face portion is contiguous to each of the first front flank face portion and the first rear flank face portion, the second rear flank face portion is contiguous to the first front flank face portion, when a ridgeline between the first front flank face portion and the first rear flank face portion is defined as a first ridgeline, and a ridgeline between the second front flank face portion and the second rear flank face portion is defined as a second ridgeline, a distance between the first ridgeline and the second ridgeline in a direction perpendicular to the first ridgeline as viewed in an axial direction from a front end toward a rear end of the drill is greater than 0 mm and less than or equal to 0.03 mm, a ridgeline between the first front flank face portion and the second rear flank face portion constitutes a first chisel region, a ridgeline between the first rear flank face portion and the second front flank face portion constitutes a second chisel region, a ridgeline between the first front flank face portion and the second front flank face portion constitutes a third chisel region contiguous to each of the first chisel region and the second chisel region, the third chisel region is provided at the front end, a ridgeline between the first thinning face and the first flank face and a ridgeline between the first thinning face and the second flank face constitute a first thinning ridgeline, a ridgeline between the second thinning face and the first flank face and a ridgeline between the second thinning face and the second flank face constitute a second thinning ridgeline, and a shortest distance between the first thinning ridgeline and the second thinning ridgeline in a direction perpendicular to the first ridgeline as viewed in the axial direction is greater than or equal to 0.04 mm and less than or equal to 0.10 mm. ### Claim 2 (depends on 1) The drill according to claim 1, wherein the third chisel region has a length that is greater than or equal to 23% and less than or equal to 55% of the shortest distance as viewed in the axial direction. ### Claim 3 (depends on 1) The drill according to claim 1, wherein the drill has an edge diameter of less than or equal to 3 mm. ### Claim 4 (depends on 3) The drill according to claim 3, further comprising: a first chip discharge face helically provided around the axis and contiguous to the first flank face, and a second chip discharge face helically provided around the axis and contiguous to the second flank face, wherein each of the first chip discharge face and the second chip discharge face constitutes a chip discharge flute, and a length of each of the first chip discharge face and the second chip discharge face in the axial direction is greater than or equal to 2 times and less than or equal to 10 times the edge diameter. ### Claim 5 (depends on 4) The drill according to claim 4, wherein a ridgeline between the first flank face and the first chip discharge face constitutes a first cutting edge, a ridgeline between the second flank face and the second chip discharge face constitutes a second cutting edge, a rake angle of the first cutting edge in a radial direction of the drill at an outermost peripheral end of the first cutting edge is greater than or equal to −18° and less than or equal to −9°, and a rake angle of the second cutting edge in the radial direction of the drill at an outermost peripheral end of the second cutting edge is greater than or equal to −18° and less than or equal to −9°. ### Claim 6 (depends on 1) The drill according to claim 1, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is larger than an angle formed by the first ridgeline and the first chisel region and larger than an angle formed by the first ridgeline and the second chisel region. ### Claim 7 (depends on 1) The drill according to claim 1, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 8 (depends on 1) The drill according to claim 1, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 9 (depends on 2) The drill according to claim 2, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 10 (depends on 3) The drill according to claim 3, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 11 (depends on 4) The drill according to claim 4, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 12 (depends on 5) The drill according to claim 5, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 13 (depends on 6) The drill according to claim 6, wherein an angle formed by the first ridgeline and the third chisel region as viewed in the axial direction is greater than or equal to 50° and less than or equal to 80°. ### Claim 14 (depends on 2) The drill according to claim 2, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 15 (depends on 3) The drill according to claim 3, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 16 (depends on 4) The drill according to claim 4, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 17 (depends on 5) The drill according to claim 5, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 18 (depends on 6) The drill according to claim 6, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°. ### Claim 19 (depends on 7) The drill according to claim 7, wherein an angle formed by the first ridgeline and the first chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°, and an angle formed by the first ridgeline and the second chisel region as viewed in the axial direction is greater than or equal to 40° and less than or equal to 60°.