Provided is a method of drilling a hole in a drilling object by using a hole drilling device 1 including: a drill bit 3 including a cutting edge on a distal end thereof; and an electric drill 2, which rotates the drill bit 3, the method including a cutting step of rotating the drill bit 3 to drill a hole in the drilling object in a state where a water-soluble gel coolant is applied to the distal end of the drill bit 3.

The invention relates to a single-lip deep hole drill comprising a drill head, wherein the drill head has a drill diameter, a blade and a channel for chip removal, wherein the blade extends outwards from a rotational axis (23) up to the perimeter of the drill head, wherein the blade has a cutting surface (33) and wherein the channel is bordered by a chip forming surface (15), wherein the chip forming surface (15) has two sections (19, 21) such that a first section (19) of the chip forming surface (15) extends in the radial direction from the rotational axis (23) up to a first diameter, a second section (21) of the chip forming surface (15) connects to the first section (19) in the radial direction, the first section (19) is positioned above the cutting surface (33), and the second section (21) is positioned nearer to the cutting surface (33) than the first section (19). (H1>0; H1>H2)

A power tool including a housing with left and right side walls, a rear wall extending between the left and right side walls, a left angled wall extending between the left side wall and the rear wall and a right angled wall extending between the right side wall and the rear wall. The power tool also includes a handle extending from the housing and defining a gap between the handle and the rear wall of the housing, a motor located within the housing, a fan driven by the motor, and a spindle driven by the motor to rotate about an axis. The left and right angled walls converge inwardly toward the axis in a front-to-rear direction along the axis. The housing includes air intake openings located on the left and right angled walls. Rotation of the fan draws an airflow into the housing through the air intake openings.

A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surf ace that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.

A rotating cutting tool that is internally cooled by cryogenic fluid has a generally cylindrical outer shape. At least one flute is formed on the cutting tool and a cutting edge is formed on an outer edge of the flute for cutting a workpiece. An internal cold flow delivery path for cryogenic coolant is in proximity to the cutting edge. A coolant cavity is formed in the cutting tool for supplying cryogenic coolant to the internal cold flow delivery path and a return path for cryogenic coolant is downstream from the cold flow delivery path. An exhaust port is coupled to the return path for exhausting cryogenic coolant to atmosphere. The exhaust port is remote from the cutting edge so that the cryogenic coolant is exhausted away from the cutting edge and away from a workpiece so that the cryogenic coolant does not cool and toughen the workpiece.

A single-lip drill including at least one cutting edge on a drill head has a face which is concave along at least 75 percent of the width thereof and substantially along the entire length thereof, all the way to, and inclusive of, the cutting edge.

A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surface that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.

A tool coupling arrangement for drills and reamers includes tool and shank portions with respective tool and shank axial stoppers. An at least partially cylindrical tool coupling end of the tool portion is located within a longitudinal through forward bore portion in the shank portion, and being coupled therein via an elongated coupling member located further inwards in the shank portion and comprising axially opposite member coupling and pulling ends. The forward bore portion has front and rear sub-portions and a bore recess which is located therebetween and extends radially outwardly. In a locked position, the tool axial stopper abuts the shank axial stopper. The tool coupling end abuts the front and rear sub-portions. And the member coupling end is wedged between the tool coupling end and the bore recess.

A rotating cutting tool configured to rotate around an axis of rotation in a rotary direction, and a support pad for such a tool is disclosed. The support pad defines a central longitudinal axis and has a first longitudinal edge side, an opposite second longitudinal edge side, a first transversal edge side and an opposite second transversal edge side. The support pad includes a first support surface, which is convexly curved as viewed in a plane perpendicular to the central longitudinal axis and a first recess, which extends into the first support surface in a direction from the first longitudinal edge side towards the second longitudinal edge side. The first recess extends to a final position on the first support surface.