A blade-shaped cutting insert has opposing first and second insert side surfaces with a peripheral surface extending therebetween, and a first cutting portion having a first primary cutting edge extending between the first and second insert side surfaces, defining a maximum insert width of the cutting insert. The peripheral surface includes an upper surface and first and second diverging flank surfaces bisected by a first plane transverse to the upper surface. The cutting insert has a maximum insert length measured perpendicular to the first plane which is more than sixteen times greater than the maximum insert width, and a maximum insert height measured parallel to the first plane which is more than ten times greater than the maximum insert width. The cutting insert is removably secured in an insert receiving pocket of a tool holder, which is defined by an upper clamping jaw and a lower clamping jaw.

A cutting tool includes a cutting chip and a chip holder. The chip holder includes: a body part having a height dimension larger than a width dimension, the body part including a first attachment face that intersects with a cutting feed direction, and a second attachment face that intersects with the first attachment face; a chip support part whose base end portion is connected to the body part and in which the cutting chip is attached to the upper end portion in the height direction of a tip end portion of the chip support part such that the cutting chip projects to one side in the width direction of the chip support part; a reinforcement part provided along the height direction of the chip support part; and a chip receiving part that supports the cutting chip projecting from the chip support part.

Provided is a cutting tool that simultaneously improves both fracture resistance and wear resistance. The cutting tool according to the present invention has an end surface, a peripheral side surface intersecting with the end surface, and a cutting edge in an intersecting ridge part along the end surface and the peripheral side surface, and when first and second points A and B are defined on the cutting edge, the first point A protrudes further toward an outer side of the cutting tool than the second point B. The cutting edge has a honing surface. The honing surface has a portion, the width of which gradually increases from the first point A toward the second point B.

A high-speed grooving method includes: a dummy machining step of machining a dummy groove in the surface of the workpiece by moving the cutting tool relative to the workpiece in a first direction, then turning the cutting tool 180 degrees, and subsequently further machining the dummy groove by moving the cutting tool in a second direction opposite to the first direction; a step of measuring a displacement of the cutting edge of the cutting tool, caused by the inversion of the cutting tool, from the dummy groove formed in the surface of the workpiece; a forward-stroke machining step of machining a groove with the cutting tool in the surface of the workpiece by moving the cutting tool relative to the workpiece in the first direction; a cutting tool inversion step of turning the cutting tool 180 degrees after completion of the forward-stroke machining step, thereby setting the direction of the cutting edge of the cutting tool to a direction opposite to the first direction so that the workpiece can be machined during a return stroke of the cutting tool; a correction step of correcting the relative position between the workpiece and the cutting tool so as to eliminate the displacement; and a return-stroke machining step of further machining the groove, which has been machined in the forward-stroke machining step, with the cutting tool by moving the cutting tool relative to the workpiece in the direction opposite to the first direction.

Provided is a cutting tool in which one end side of a protruding cutting edge is sharpened while wear resistance is improved. The cutting tool of the present invention includes an end surface, a peripheral side surface that intersects the end surface, and a cutting edge in an intersecting ridgeline portion between the end surface and the peripheral side surface. When first and second points (A and B) are set on the cutting edge, the first point (A) protrudes further toward an outer side of the cutting tool than the second point (B). The cutting tool has a coating film on its surface. The cutting edge has a portion in which the thickness of the coating film gradually increases toward the second point (B) from the first point (A).

A method for producing a piston for internal combustion engines, where the piston includes a circumferential trapezoid annular groove for receiving trapezoid rings with small axial dimensions the groove having a groove base with adjoining surfaces and groove flanks. The groove base with adjoining surfaces is created in a first method step by machining using a cutting steel tool and the groove flanks are created in a further method step. Also disclosed are a piston produced according to the method and a cutting steel tool.

A holder for a cutting tool of the present disclosure extends from a first end toward a second end, and includes an inflow port, an outflow port located at a side of the first end, and a flow path extending from the inflow port toward the outflow port. The outflow port includes a first opening and a second opening. The flow path includes a first flow path extending continuously from the inflow port, a second flow path extending continuously from the first flow path through a first branch port to the first opening, and a third flow path extending continuously from the first flow path through a second branch port to the second opening. The first branch port is larger than the second branch port. An outflow through the first opening is greater than an outflow through the second opening.

A cutting tool includes a two-way indexable cutting insert retained in a tool holder by a clamping member. The cutting insert has a tetrahedral basic shape and includes two cutting edges at opposite ends of thereof. The insert holder includes a forwardly located mounting portion that includes three spaced apart mounting jaws which together define an insert receiving pocket having a pocket opening. The clamping member is attached to the insert holder body so that a clamping portion of the clamping member protrudes into the pocket opening. When the cutting insert is releasably attached to the insert holder in a fastened position of a cutting tool, the cutting insert is located in the insert receiving pocket and clampingly engaged therein by the clamping portion.

A body of a cutting tool and a cutting insert which can further improve support stiffness of the cutting insert are provided.

A body of a cutting tool includes an insert seat provided on a leading end part of the body, a screw hole with which a fastening screw is screwed, a deep seat portion provided at a deep part in the insert seat in an axial direction of the screw hole, a receiving portion receiving a contact portion of the cutting insert, a wall portion having a base-end side rotation suppression portion which stops rotation of the cutting insert, and a shallow seat portion, the depth of a seat thereof being shallower than a part with the receiving portion, wherein the base-end side rotation suppression portion is positioned not to overlap the deep seat portion when viewed along a screw-hole axis.

A cutting insert includes a leading cutting edge having a rake angle in the range of 20 to 35 in a central region in a width direction; and a rake face having a breaker groove formed in the central region in the width direction and land portions formed in both end regions in the width direction. The land portions have a rake angle smaller than the rake angle in the central region in the width direction. The breaker groove includes opposing side faces separated from each other by a distance that decreases with increasing distance from the leading cutting edge and four shoulder portions of the same height that are formed on the opposing side faces at positions above the land portions, two of the shoulder portions being closer to the leading cutting edge and to outer sides in the width direction than the other two shoulder portions are.