A surface coated cutting tool comprises: a tool substrate and a coating layer on a surface of the tool substrate; wherein the coating layer comprises a lower layer, an intermediate layer, and an upper layer, in sequence from the tool substrate toward the surface of the tool. The lower layer comprises an A layer having an average composition represented by formula: (Al.sub.1-xCr.sub.x)N, where x is 0.20 to 0.60; the intermediate layer comprises a B layer having an average composition represented by formula: (Al.sub.1-a-bCr.sub.aSi.sub.b)N, where a is 0.20 to 0.60 and b is 0.01 to 0.20; and the upper layer comprises a C layer having an average composition represented by formula: (Ti.sub.1-α-βSi.sub.αW.sub.β)N where α is 0.01 to 0.20 and β is 0.01 to 0.10; and the upper layer has a repeated variation in W level with an average interval of 1 nm to 100 nm between adjacent local maxima and minima.

A cutting tool includes a shaft portion. The shaft portion includes an increased-diameter portion having a diameter larger than a diameter of other portion of the shaft portion. The increased-diameter portion has a recessed portion formed in a peripheral surface of the increased-diameter portion.

A ridgeline between the thinning face and the flank face includes a first thinning portion contiguous to the outer cutting edge, and a second thinning portion contiguous to the first thinning portion. When viewed in a direction along the central axis, the first thinning portion is linear and the second thinning portion is curved. When viewed in the direction along the central axis, the first thinning portion, and a boundary between the first thinning portion and the second thinning portion are located rearward in a rotational direction relative to a first straight line, and are located forward in the rotational direction relative to a second straight line, the first straight line being a straight line passing through the central axis and parallel to the first thinning portion, and the second straight line being a straight line perpendicular to the first straight line.

A rotary cutting tool includes a tool body and a cutting edge tip provided at the tool body. At least one first groove is provided in a rake face of the cutting edge tip, the first groove has a portion inclined with respect to a rotation axis, and a front end of the first groove is provided at a front cutting edge. A rear end of the first groove is provided on an inner side with respect to an outer peripheral cutting edge, and an irregularity of the outer peripheral cutting edge is 30 μm or less.

A rotary cutting tool includes a tool body and a cutting edge tip provided at the tool body. At least one first groove is provided in a rake face of the cutting edge tip, the first groove has a portion inclined with respect to a rotation axis, and a front end of the first groove is provided at a front cutting edge. A rear end of the first groove is provided on an inner side with respect to an outer peripheral cutting edge, and an irregularity of the outer peripheral cutting edge is 30 μm or less.

A cutting tool may include a base member and a diamond layer located on the base member. The cutting tool may include a first surface, a second surface, and a cutting edge located in at least a part of a ridge line which the first surface intersects with the second surface. The diamond layer may be located in at least a part of the first surface, at least a part of the second surface, and at least a part of the cutting edge. A maximum height in the cutting edge may be smaller than a maximum height in the first surface. The maximum height in the cutting edge may be greater than a maximum height in the second surface.

A drill includes drill body and peripheral insert having a radial cutting edge extending generally in a direction of a radius of the drill body, and a central insert. The peripheral insert includes a rake face including a plurality of chipbreaker protrusions. A first angle measured between a line tangent to forward ends of the plurality of chipbreaker protrusions and the central axis of the drill body extending toward the shank end is an acute angle. Also a peripheral insert is disclosed.

A spigot stop removal bit device facilitates removal of a buried spigot stop without having to dig. The device includes a first bit and a second bit each having a respective first end configured for coupling to a driving tool to be selectively rotated by the driving tool. A second end of the first bit is flat. A second end of the second bit is sharpened wherein the second end of the second bit is configured for engaging and cutting into the plug wherein the plug is structurally compromised to facilitate removal of remnants of the plug from the hydrant pipe. Respective lengths of the first bit and the second bit are extended such that the second end of each is configured for engaging a plug positioned in a hydrant pipe.

A spigot stop removal bit device facilitates removal of a buried spigot stop without having to dig. The device includes a first bit and a second bit each having a respective first end configured for coupling to a driving tool to be selectively rotated by the driving tool. A second end of the first bit is flat. A second end of the second bit is sharpened wherein the second end of the second bit is configured for engaging and cutting into the plug wherein the plug is structurally compromised to facilitate removal of remnants of the plug from the hydrant pipe. Respective lengths of the first bit and the second bit are extended such that the second end of each is configured for engaging a plug positioned in a hydrant pipe.

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 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 at least two 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.