A turning insert includes a top surface, an opposite bottom surface, and a reference plane located parallel to and between the top and the bottom surfaces. A nose portion includes a convex nose cutting edge, and a first and a second cutting edge. The nose cutting edge connects the first and second cutting edges. The first and second cutting edges form a nose angle of 71-85° relative to each other. The nose portion has a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third convex cutting edge. The fourth cutting edge forms an angle of 10-30° relative to a bisector. The distance from at least a portion of the fourth cutting edge to the reference plane increases at an increasing distance from the nose cutting edge. A second protrusion is arranged between the nose cutting edge and the first protrusion.

A cutting insert according to the present disclosure includes a first raised portion and a second raised portion stepped from the first raised portion, which are formed on a top surface and along a center line connecting the center of the corner portion and the center of the top surface. The first raised portion is located closer to the corner portion than the second raised portion is, and the first raised portion is inclined downwardly from the second raised portion toward the corner portion. The second raised portion is formed at a higher position from the bottom surface than the first raised portion, and a side portion connected to the first raised portion is inclined downwardly from the second raised portion toward the first and second cutting edges.

A cutting tool insert includes eight identical cutting edges. Each separate cutting edge has a first cutting edge portion and a second cutting edge portion. A corner angle between the first cutting edge portion and the second cutting edge portion is within a range of 75 to <90 degrees. The first cutting edge portion and the second cutting edge portion have substantially the same length to provide a substantially equal cutting depth. As seen along the center axis of the insert a first angle within a range of 14+/−9 degrees is formed between a first imaginary line extending from the center axis to a corner point at the first side surface and a second imaginary line extending from the center axis to an adjacent corner point at the second side surface. A cutting tool insert holder is also disclosed.

A cutting edge includes a nose portion, a first cutting edge portion, and a second cutting edge portion. When a boundary between a first inclined portion and a first breaker portion, a boundary between a first step surface and a second breaker portion, a boundary between a second inclined portion and a third breaker portion, and a boundary between a second step surface and a fourth breaker portion are a first position, a second position, a third position, and a fourth position, respectively, the second position is higher than the first position and the fourth position is higher than the third position in a direction perpendicular to the seating surface, and a distance between the first position and the third position is greater than a distance between the second position and the fourth position in a direction parallel to the seating surface.

There is provided a machining assembly and cutting insert for machining metal or like workpieces, wherein the cutting insert body has a cutting end. The cutting end comprises at least one cutting edge and at least one cutting lip formed adjacent the at least one cutting edge. The at least one cutting lip includes at least one cutting protrusion and associated chip cutting edge to split the chip formed by the at least one cutting edge, for producing chips during machining which are of a width that is sufficiently reduced to allow proper evacuation or removal.

A cutting insert according to the present disclosure includes a first raised portion and a second raised portion stepped from the first raised portion, which are formed on a top surface and along a center line connecting the center of the corner portion and the center of the top surface. The first raised portion is located closer to the corner portion than the second raised portion is, and the first raised portion is inclined downwardly from the second raised portion toward the corner portion. The second raised portion is formed at a higher position from the bottom surface than the first raised portion, and a side portion connected to the first raised portion is inclined downwardly from the second raised portion toward the first and second cutting edges.

There is provided a cutting insert used for both drilling and turning. The cutting insert includes an insert main body having a front surface and a rear surface, the outline shapes of which are parallelogram shapes, peripheral side surfaces disposed on four sides of the insert main body, cutting edges provided on respective intersecting ridge lines between the front surface and the peripheral side surface and between the rear surface and the peripheral side surface of the insert main body, and a hole provided in the insert main body to incline with respect to the front surface and the rear surface, the hole being usable for attachment.

There is provided a machining assembly and cutting insert for machining metal or like workpieces, wherein the cutting insert body has a cutting end. The cutting end comprises at least one cutting edge and at least one cutting lip formed adjacent the at least one cutting edge. The at least one cutting lip includes at least one cutting protrusion and associated chip cutting edge to split the chip formed by the at least one cutting edge, for producing chips during machining which are of a width that is sufficiently reduced to allow proper evacuation or removal.

A turning insert includes a top surface, an opposite bottom surface, and a reference plane located parallel to and between the top and the bottom surfaces. A nose portion includes a convex nose cutting edge, and a first and a second cutting edge. The nose cutting edge connects the first and second cutting edges. The first and second cutting edges form a nose angle of 71-85° relative to each other. The nose portion has a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third convex cutting edge. The fourth cutting edge forms an angle of 10-30° relative to a bisector. The distance from at least a portion of the fourth cutting edge to the reference plane increases at an increasing distance from the nose cutting edge. A second protrusion is arranged between the nose cutting edge and the first protrusion.

A cutting tool shim is to be disposed between a cutting insert and a holder and to be fixed to the holder. The ridgeline between the flank face and the rake face forms a cutting edge. The cutting edge includes an arc-shaped portion. A coolant supply path for jetting coolant to the arc-shaped portion is provided in the cutting tool shim, the coolant being supplied from the holder. The coolant supply path includes a lead-in port for leading the coolant from the holder to the coolant supply path, and a jetting port for arc-shaped portion for jetting the coolant to the arc-shaped portion. The jetting port for arc-shaped portion has a curved shape along the arc-shaped portion. The distance between the jetting port for arc-shaped portion and the arc-shaped portion is not less than 2.2 mm and not more than 8.1 mm.