A boring device according to one embodiment of the present invention includes: a cutting edge; a drive unit that rotationally drives the cutting edge; a feed flow path through which a cooling liquid is fed to the cutting edge; and a tube pump that forces the cooling liquid in the feed flow path to flow to the cutting edge. The tube pump includes a feed tube constituting a part of the feed flow path and a first pressing mechanism that presses the feed tube, and the first pressing mechanism is driven by the drive unit.

A drilling tool is provided, which is configured to prevent an insufficient chip discharge ability thereof. The drilling tool includes a cutting insert having a cutting edge at a leading end portion, and a body to which the cutting insert is mounted. The drilling tool also includes a recessed part provided on an outer peripheral surface of the body and extending to a leading end of the body, and an oil supply port provided on a base end side of the recessed part and supplying cutting oil, passing through the inside of the body, to an outer peripheral side of the body. In a case where the drilling tool further includes a guide pad that comes into abutment with an inner wall surface of a hole cut by the cutting insert, and a fastening screw for fixing the guide pad to the body, the oil supply port may be provided at a position further toward the base end side of the body than a position of the fastening screw.

A drilling tool is provided, which is configured to prevent an insufficient chip discharge ability thereof. The drilling tool includes a cutting insert having a cutting edge at a leading end portion, and a body to which the cutting insert is mounted. The drilling tool also includes a recessed part provided on an outer peripheral surface of the body and extending to a leading end of the body, and an oil supply port provided on a base end side of the recessed part and supplying cutting oil, passing through the inside of the body, to an outer peripheral side of the body. In a case where the drilling tool further includes a guide pad that comes into abutment with an inner wall surface of a hole cut by the cutting insert, and a fastening screw for fixing the guide pad to the body, the oil supply port may be provided at a position further toward the base end side of the body than a position of the fastening screw.

A single-edge drill for forming a deep hole is provided which includes a body and a shank. The body has a single chip discharge groove in the outer periphery thereof, and includes a small-diameter portion, and a large-diameter portion having coolant delivery grooves in the outer periphery thereof. The body has a core thickness at the distal end portion of the large-diameter portion. At the other portion of the body, the groove bottom of the chip discharge groove is located beyond the rotation center of the drill such that the body has no core thickness, and when taken perpendicularly to the axial direction of the drill, the cross section of the body has a crescent shape. When a hole is formed with the drill, a supply path for coolant liquid is defined between the outer peripheral surface of the small-diameter portion and the radially inner surface of the hole.

A single-edge drill for forming a deep hole is provided which includes a body and a shank. The body has a single chip discharge groove in the outer periphery thereof, and includes a small-diameter portion, and a large-diameter portion having coolant delivery grooves in the outer periphery thereof. The body has a core thickness at the distal end portion of the large-diameter portion. At the other portion of the body, the groove bottom of the chip discharge groove is located beyond the rotation center of the drill such that the body has no core thickness, and when taken perpendicularly to the axial direction of the drill, the cross section of the body has a crescent shape. When a hole is formed with the drill, a supply path for coolant liquid is defined between the outer peripheral surface of the small-diameter portion and the radially inner surface of the hole.

A cutting tool 10 includes: a shank part 14 that is substantially cylindrical in shape and provided at a base end portion 10b of the cutting tool 10; a cutting edge 18 located at a leading end portion 10t of the cutting tool 10; a chip discharge groove 30 formed from the cutting edge 18 toward the base end portion 10b of the cutting tool 10, for guiding and discharging chips generated during cutting; and a plurality of groove-like coolant flow paths 40 provided on a periphery of the cutting tool 10, for supplying coolant toward the leading end portion 10t. In a leading end view where the cutting tool 10 is viewed from the leading end portion 10t along the central axis 10A extending in a longitudinal direction of the cutting tool 10, a first coolant flow path 41 of the plurality of coolant flow paths 40 is located at an upper side relative to the cutting edge 18.