A twist drill and an exchangeable head for a twist drill, the twist drill extending along a central axis of rotation and having a front end formed as a drill point with two cutting edges and at least two clearance surfaces. Two helical chip flutes conduct chips away from the cutting edges. Each cutting edge extends in a transition between the clearance surfaces. One of the chip flutes extends from an inner position adjacent to the central axis to a peripheral envelope surface and has a main portion closest to the peripheral envelope surface. Each chip flute is delimited by a side surface including a main rake face, which extends rearward from the main portion of the cutting edge. The cutting edges are contained in an imaginary conical surface, such that the twist drill is operable to generate a bottom profile having the shape of an inverted cone.

A rotary cutting tool includes a tool body including a chip flute portion having a plurality of helical chip flutes separated by lobes. In one aspect, a tunable vibration absorber assembly is disposed within a cavity formed in the chip flute portion. In another aspect, the tunable vibration absorber assembly is disposed within a cavity of a replaceable cutting head. In each aspect, the tunable vibration absorber assembly includes one or more tunable absorber masses, a resilient material between the one or more absorber masses and the cavity, and one or more connecting members for preventing relative angular displacement of the one or more tunable absorber masses. The one or more tunable absorber masses are suspended only by the resilient material, thereby enabling the tunable vibration absorber assembly to be tuned to a desired frequency for suppressing torsional vibration of the rotary cutting tool during a cutting operation.

A drill body is provided which enables a cutting edge member to be readily correctly mounted to a leading end part of the drill body and which can suitably supply a cutting region with a cutting fluid. The drill body includes: a body part which extends in a rod shape from a base end part toward a leading end part; a fluid hole for causing a fluid to flow inside the body part from a side of the base end part toward a side of the leading end part; and a mounting part which is provided in the leading end part and which is for mounting a removable cutting edge member, wherein the mounting part has a recessed part which is provided along a central axis of the body part from an end surface of the leading end part, and the fluid hole is provided by being bent in a side part of the recessed part so that a discharge port of the fluid hole in the leading end part opposes a cutting edge of the cutting edge member when the cutting edge member is mounted to the mounting part as prescribed.

A rotary cutting tool includes a tool body including a chip flute portion having a plurality of helical chip flutes separated by lobes. In one aspect, a tunable vibration absorber assembly is disposed within a cavity formed in the chip flute portion. In another aspect, the tunable vibration absorber assembly is disposed within a cavity of a replaceable cutting head. In each aspect, the tunable vibration absorber assembly includes at least two tunable absorber masses, a resilient material between the one or more absorber masses and the cavity, and one or more connecting members for preventing relative angular displacement of the one or more tunable absorber masses. The at least two tunable absorber masses are suspended only by the resilient material, thereby enabling the tunable vibration absorber assembly to be tuned to a desired frequency for suppressing torsional vibration of the rotary cutting tool during a cutting operation.

A cutting insert for a rotary drill tool and a drill tool assembly in which an insert and a support body are coupled via cooperative contact surfaces and a mounting screw. The contact surfaces provide a dual function to axially and rotationally lock the insert at the support body in addition to providing a centring function of the insert.

A tool tip is integral with or removably secured to a tool body and configured to machine a metal object. The tool tip has a tool tip diameter, a rotational axis and at least one coolant duct. The tool tip includes at least one major cutting edge formed at an intersection of a rake face and a first major flank. The rake face forms part of a chip flute. The coolant duct is configured to be in flow communication with discharge orifices located exclusively in the tool tip. The tool tip has an arrangement, such as a row of two or more discharge orifices located exclusively in the rake face of a major cutting edge. The arrangement extends at a non-zero angle relative to the rotational axis.

A rotary cutting tool includes a tool body including a chip flute portion having a plurality of helical chip flutes separated by lobes. In one aspect, a tunable vibration absorber assembly is disposed within a cavity formed in the chip flute portion. In another aspect, the tunable vibration absorber assembly is disposed within a cavity of a replaceable cutting head. In each aspect, the tunable vibration absorber assembly includes one or more tunable absorber masses, a resilient material between the one or more absorber masses and the cavity, and one or more connecting members for preventing relative angular displacement of the one or more tunable absorber masses. The one or more tunable absorber masses are suspended only by the resilient material, thereby enabling the tunable vibration absorber assembly to be tuned to a desired frequency for suppressing torsional vibration of the rotary cutting tool during a cutting operation.

A drill may be extended from a first end to a second end and may include a cutting part. The cutting part may include a cutting edge, a flute, an end surface and a connection surface. The flute may be extended from the cutting edge toward the second end. The end surface may be located closer to the second end than the flute. The connection surface may be located between the flute and the end surface. The connection surface may include a first portion, and a second portion located closer to an outer periphery of the cutting part than the first portion. A length in the direction along the rotation axis on the second portion may be smaller than a length in the direction along the rotation axis on the first portion in a side view orthogonal to the rotation axis.

A cutting head rotatable about a first axis, comprising an intermediate portion and a tip portion. The intermediate portion has a plurality of leading edges defining a cutting diameter, and the tip portion has an axially forwardmost tip point and a plurality of front surfaces with outer and inner cutting edges. An outer rake surface adjacent to each outer cutting edge has a positive outer rake angle, and an inner rake surface adjacent to each inner cutting edge has a negative inner rake angle. Each outer rake surface is disposed on a head flute intersecting one of the leading edges, and each inner rake surface is disposed on a gash intersecting one of the head flutes. Each gash extends to a gash path end point located a first distance axially rearward of the tip point, and the first distance is greater than thirty percent of the cutting diameter.

The present invention provides a universal fastening system that joins or affixes two or more objects together. The universal fastening system comprises a driving tool having a first end and a second end connected through a cylindrical shaft, wherein one end is a tip end having a plurality of indentations, and the other end is a tool head for receiving a driving shaft which can be rotated by a hand-driven tool or motorized tool. The system also includes a fastener comprising a head part on which a plurality of protrusion or teeth are positioned to facilitate the engagement of the fastener with the driving tool at various angles. Furthermore, the fastener also includes a shank member centrally attached to the head of the fastener, having a plurality of threads enables the insertion of the fastener within the fastening channel when rotated by the driving tool.