A drill according to an embodiment includes a bar-shaped drill body extending along a rotation axis, a cutting edge located at a front end of the drill body, and a first flute extending spirally from the cutting edge toward a rear end of the drill body. The first flute includes a first region which is located close to the front end and has a helix angle θ1, and a second region which is located closer to the rear end than the first region and has a helix angle θ2 smaller than the helix angle θ1. The second region includes an elongated protruding part along the first flute.

A drill according to an embodiment includes a bar-shaped drill body extending along a rotation axis, a cutting edge located at a front end of the drill body, and a first flute extending spirally from the cutting edge toward a rear end of the drill body. The first flute includes a first region which is located close to the front end and has a helix angle θ1, and a second region which is located closer to the rear end than the first region and has a helix angle θ2 smaller than the helix angle θ1. The second region includes an elongated protruding part along the first flute.

An auger includes a body having a first end and a second end opposite the first end and a shank positioned at the first end of the body. The shank is configured to couple to a power tool. The auger also includes a cutting head positioned at the second end of the body. The cutting head is substantially cone shaped. The cutting head includes a feed screw and a cutting flute.

An auger includes a body having a first end and a second end opposite the first end and a shank positioned at the first end of the body. The shank is configured to couple to a power tool. The auger also includes a cutting head positioned at the second end of the body. The cutting head is substantially cone shaped. The cutting head includes a feed screw and a cutting flute.

A handheld wood thread cutting tool with an elongated shank formed with a planar surface and including a first end and a second end with a length substantially longer than its width. The first end has a first wood thread cutting edge aligned substantially in parallel relative to a first vertical plane perpendicular to the planar surface and passing through the length of the elongated shank from the first end to the second end. The second end has a second wood thread cutting edge aligned substantially parallel to a second vertical plane perpendicular to the planar surface and running through the width of the elongated shank from a first side wall to a second side wall. A ball handle is affixed between the first and the second end.

A handheld wood thread cutting tool with an elongated shank formed with a planar surface and including a first end and a second end with a length substantially longer than its width. The first end has a first wood thread cutting edge aligned substantially in parallel relative to a first vertical plane perpendicular to the planar surface and passing through the length of the elongated shank from the first end to the second end. The second end has a second wood thread cutting edge aligned substantially parallel to a second vertical plane perpendicular to the planar surface and running through the width of the elongated shank from a first side wall to a second side wall. A ball handle is affixed between the first and the second end.

A drill according to an embodiment includes a bar-shaped drill body extending along a rotation axis, a cutting edge located at a front end of the drill body, and a first flute extending spirally from the cutting edge toward a rear end of the drill body. The first flute includes a first region which is located close to the front end and has a helix angle 1, and a second region which is located closer to the rear end than the first region and has a helix angle 2 smaller than the helix angle 1. The second region includes an elongated protruding part along the first flute.