A bore cutting tool for cutting metal workpieces includes a tool substrate and a tool coating on a surface of the tool substrate. The bore cutting tool includes a plurality of pits in the surface of the tool substrate and wherein the tool coating extends over the pits such that the pit surface includes the tool coating. In this way, the pit dimensions can be retained over prolonged tool life and the pits, with their coated surface, are particularly effective at retaining lubricant so that the thickness of a lubricant film can be increased as compared to a tool without the coated pits. In the embodiments, the pits are formed by laser etching and are present only on the cylindrical land. Average pit depth is suitably in the range 8 μm to 25 μm, average pit width and pit length is independently selected from 40 μm to 250 μm and average pit density may be 20 to 30 pits/mm.sup.2.

According to one implementation, a drill has at least one cutting edge. A projected shape of a passing area of a ridgeline of the at least one cutting edge when the at least one cutting edge is rotated around a tool axis becomes a line-symmetric and discontinuous line along a parabola, two parabolas, an ellipse or two ellipses. The projected shape is drawn on a projection plane parallel to the tool axis.

A method of installing cable through material, for example, concrete, wood, masonry, plastic steel, or the like comprising a drill bit with a distal end having a hollow tip with an attachment mechanism for receiving the cable. The drill bit is drilled through the material, and left in place while the cable is attached to the proximal end of the drill bit. There is no need to remove the drill bit from the aperture or material to attach the cable thereto. After attachment to the drill bit, the cable is inserted through the aperture with the drill bit and removed from the drill bit after it passes through the material so it can be attached to a receiver device.

An automated computer-implemented method for generating commands for controlling a computer numerically controlled machine to fabricate an object from a workpiece, the method including the steps of selecting a maximum permitted engagement angle between a rotating cutting tool and the workpiece, selecting a minimum permitted engagement angle between the rotating cutting tool and the workpiece, and configuring a tool path for the tool relative to the workpiece in which the engagement angle gradually varies between the maximum permitted engagement angle and the minimum permitted engagement angle.

A fastener extraction ratchet bit system for facilitating extraction of stripped fasteners by permitting attachment of extraction bits to an air drive ratchet. The system includes a driving tool and a fitting coupled to and extending from the driving tool. A drill socket is coupled to a drill bit wherein the drill bit is selectively couplable to the fitting such that the driving tool provides a driving force to the drill bit. An extraction socket is coupled to an extraction bit wherein the extraction bit is also selectively couplable to the fitting such that the driving tool provides the driving force to the extraction bit.

A cutting insert includes a top face, a bottom face and a plurality of side walls extending between the top face and the bottom face. A central axis of the cutting insert extends through the top face and the bottom face. A peripheral cutting edge is defined at the juncture of each side wall and the top face. Each cutting edge includes a linear cutting edge portion having an end portion that connects to a concave cutting edge portion that curves inwardly in a plane that is perpendicular to a first plane containing the central axis, wherein at least one linear cutting edge portion and its corresponding end portion are parallel to the first plane containing the central axis.

A drill bit including a shaft which has a pyramidal shaped end defining a drill tip with a plurality of edges defining the pyramidal shape. One or more recesses are provided for directing away debris produced whilst drilling. At least one recess has a first portion extending along the shaft and a second portion having a first portion extending along the shaft and a second portion which extends along the drill tip. The second portion of the at least one recess extends along an edge of the drill tip.

A drill bit including a shaft which has a pyramidal shaped end defining a drill tip with a plurality of edges defining the pyramidal shape. One or more recesses are provided for directing away debris produced whilst drilling. At least one recess has a first portion extending along the shaft and a second portion having a first portion extending along the shaft and a second portion which extends along the drill tip. The second portion of the at least one recess extends along an edge of the drill tip.

A rotary cutter for cutting damaged threads of a bolt includes a body rotatable about a rotating axis. The body includes a connecting end and an operative end. The body includes an inner periphery delimiting a cutting space extending along the rotating axis from the operative end towards but spaced from the connecting end. A width of the cutting space in a diametric direction perpendicular to the rotating axis gradually reduces from the operative end toward the connecting end to form a conic space. The body further includes at least one cutting blade disposed on the inner periphery. The at least one cutting blade includes a first cutting blade section and a second cutting blade section. The first cutting blade section is arcuate or rectilinear. The second cutting blade section is arcuate or rectilinear. The first and second cutting blade sections are not identical.

A reaming tool includes a tool body having an axially rearward shank portion and an axially forward cutting portion, the forward cutting portion having at least one peripherally arranged cutting insert. The reaming tool also includes an inlet coolant channel formed in the tool body and an inlet opening at an axially rearward end of the shank portion. An outlet coolant channel is formed in the tool body and is in fluid communication with the inlet coolant channel, wherein the outlet coolant channel defines an outlet opening proximate to the cutting insert. In one particular aspect, at least a portion of the outlet coolant channel is non-linear. A method of making a component of the reaming tool by performing a printing operation on a substrate to form the component is also provided.