A cutting insert for a rotary cutting tool has a second surface that includes a second seating surface having a shape of a flat surface. The first cutting edge has a first main cutting edge portion and a first sub cutting edge portion. The second cutting edge has a second main cutting edge portion and a second sub cutting edge portion. When viewed in a direction from the first surface toward the second surface, at least a portion of the second sub cutting edge portion is located outside the first main cutting edge portion, and at least a portion of the first sub cutting edge portion is located outside the second main cutting edge portion. When viewed in the direction from the first surface toward the second surface, each of the first sub cutting edge portion and the second sub cutting edge portion has a shape of a curved line.

Milling inserts having surfaces designed for supporting the insert relative to a milling cutter body, and a milling tool are provided. The milling insert has a first end surface, a second end surface, and a side surface extending between the first end surface and the second end surface At least one cutting edge is defined by an intersection of at least one of the first end surface and the second end surface with the side surface. The at least one cutting edge includes a radiused component having a first end and a second end and first and second components at the first and the second ends of the radiused component, respectively. The first and second components are less curved than the radiused component. The side surface has at least one substantially V-shaped valley formed by first and second support surfaces.

A rotary cutting tool is provided which, although it has a simple configuration, allows the arrangement of each cutting edge to be easily adjusted. A first cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a first recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A second cartridge mounting seat has an upper wall surface opposing an outer side surface of a cartridge and further has a second recessed part into which a protrusion is inserted and which comes into contact, at a bottom thereof, with a leading end of the protrusion. A depth of the second recessed part is greater than a depth of the first recessed part. An amount of protrusion P of the protrusion is equal to or greater than the depth of the second recessed part.

An indexable cutting insert has opposing upper and lower end surfaces, and a peripheral surface including three side surfaces and three corner surfaces. Each corner surface intersects the upper end surface to form an upper cutting edge, and each side surface has a locating surface. The lower end surface has three radially outward facing lower abutment surfaces. The three locating surfaces define a first imaginary triangle having three first bisector planes and three locating planes, and the three lower abutment surfaces define a second imaginary triangle having three second bisector planes. None of the first and second bisector planes are coplanar, and each locating plane intersects two of the upper cutting edges. For each index position of the cutting insert in an insert receiving pocket of a cutting tool, one of the locating surfaces and one of the lower abutment surfaces is in contact with pocket walls thereof.

The technical objective of the present invention is to provide a cutting insert that has an improved fastening property with a cutting tool, thereby preventing reduction of the service life. To this end, the cutting insert according to the present invention has three corners along the circumference thereof; an upper main cutting edge, which is formed on the edge between the upper surface and the first side surface, and an upper sub cutting edge, which is formed on the edge between the upper surface and the second side surface, are continuously disposed between respective corners; the lower surface has the same shape as that of the upper surface; and the angle defined between the upper main cutting edge and the upper sub cutting edge, which are placed on both sides with reference to each corner, is larger than or equal to 85? and is smaller than 90?.

A double-sided milling insert for high feed milling of metal workpieces includes upper and lower faces facing in opposite directions and convex clearance surfaces extending between the upper and lower faces. Each one of the faces includes a recessed support surface. The support surfaces are substantially parallel to each other and have a cavity therein for receiving a fastening device. Intersections of the convex clearance surfaces with the upper and lower faces form convex cutting edges when seen in a plan view. A rake face is provided adjacent the convex cutting edges. Each convex cutting edge is concave when seen in a side view and includes a substantially straight cutting edge portion on each side of a curved cutting edge portion when seen in plan view. A milling tool with a plurality of such inserts and a method of high feed milling using this tool are also disclosed.

A double-sided milling insert for high feed milling of metal workpieces includes upper and lower faces facing in opposite directions and convex clearance surfaces extending between the upper and lower faces. Each one of the faces includes a recessed support surface. The support surfaces are substantially parallel to each other and have a cavity therein for receiving a fastening device. Intersections of the convex clearance surfaces with the upper and lower faces form convex cutting edges when seen in a plan view. A rake face is provided adjacent the convex cutting edges. Each convex cutting edge is concave when seen in a side view and includes a substantially straight cutting edge portion on each side of a curved cutting edge portion when seen in plan view. A milling tool with a plurality of such inserts and a method of high feed milling using this tool are also disclosed.

A crankshaft milling cutter has a disc-shaped main body rotatable about an axis perpendicular to the disc plane and on the periphery recesses for receiving indexable cutting inserts for removing an allowance on the crankshaft blank. At least some of the recesses are open both in the radial direction and in at least one axial direction of the main body and a first group of said recesses receives cutting inserts designed for removing the allowance on an oil collar adjoining a shaft journal. To provide a crankshaft milling cutter able to meet the increasing requirements with regard to dimensional and positional tolerances placed on a crankshaft milling cutter and at the same time reduces the time needed for fine adjustment of the crankshaft milling cutter, only some of the first group of recesses has devices for setting the axial position of the indexable cutting insert received in each case therein.

An internal milling cutter for producing a recess terminating in a radius in a workpiece, in particular for milling a crankshaft, comprises a tool holder having interchangeable cutting inserts detachably attached thereto. For the production of the radius, a plurality of first interchangeable cutting inserts are provided, which are arranged one after another in the direction of cut and have cutting edges which produce complementary portions of the radius, wherein the first interchangeable cutting inserts for producing the radius are identically configured.

A cutting insert includes an insert body having a polygonal plate shape. Rake faces are formed on polygonal surfaces of the insert body, and flank faces are formed on lateral faces of the insert body arranged around the polygonal surfaces. Main cutting edges are formed on side ridges of the polygonal surfaces at intersecting ridgelines between the rake faces and the flank faces. Each main cutting edge extends between two corners adjacent to each other in a circumferential direction of the polygonal surface among corners of the polygonal surface. When seen from a direction opposing the rake face, one end portion of the main cutting edge that stretches to one corner of the two corners has a convexly curved shape, and the other end portion of the main cutting edge that stretches to the other corner of the two corners has a concavely curved shape.