A rotary cutting method includes producing a processed product by rotary cutting of a workpiece by a rotary tool. The rotary tool has at least one cutting edge of which both of a first rake angle in a rotation radial direction and a second rake angle in a rotation axis direction are negative. The at least one cutting edge has a slanted face connected with a rake face forming the first and second rake angles. The slanted face is connected with the rake face at a ridge line. The slanted face faces a rotating direction of the rotary tool. An angle of the slanted face to the rotation axis direction is positive.

Provided is a cutting insert, which has excellent chip discharge performance even when formed with multiple corners superior in economic efficiency. A first ridgeline at which an upper surface and a circumferential side surface intersect each other includes a plurality of corners disposed at equal intervals and a plurality of main cutting edges disposed one by one between the corners adjacent to each other. A distance between the corners adjacent to each other is equal to or less than 60% of the diameter of a circle inscribed within the ridgeline. The main cutting edges includes a first cutting edge that is linearly formed and a second cutting edge that is linearly formed. The length of the second cutting edge is equal to or less than half the length of the first cutting edge and is positioned closer to a center side of the cutting insert than an extension line of the first cutting edge is. The circumferential side surface includes a first side surface facing the first cutting edge and a second side surface facing the second cutting edge. A clearance angle of the first side surface is smaller than that of the second side surface.

To provide a cutting insert that is properly manufactured with ease of use. A cutting insert has a first end face, a second end face on the opposite side from the first end face, and a peripheral side surface that is parallel to a central axis connecting the center of the first end face and the center of the second end face and connects the first end face and the second end face. A first major cutting edge is formed on the outer edge of the first end face. A first flank facing the first major cutting edge is formed between the first major cutting edge and the peripheral side surface and has a negative clearance angle α with respect to the peripheral side surface. The peripheral side surface includes a first side surface facing the first flank. Between the first flank and the first side surface, a recess line is formed to extend along a virtual edge line where a virtual plane extending from the first flank and a virtual plane extending from the first side surface cross each other, and the recess line is formed with a notch on the virtual edge line.

Provided is a cutting insert which is resistant to breakage and can stably be restrained. A cutting insert configured as a vertically mounted insert has a first rake face adjacent to a first major cutting edge, a second rake face adjacent to a second major cutting edge, a restraint surface located further inward than the first and second rake faces to come into contact with a tool body when a second end surface is used, and a reinforcing portion projecting from the restraint surface. The reinforcing portion has a third projecting ridge provided to extend between the first and second rake faces and halve the restraint surface, a first projecting ridge connected to one end of the third projecting ridge to extend so as to cover at least a portion of a boundary between the first rake face and the restraint surface, and a second projecting ridge connected to another end of the third projecting ridge so as to cover at least a portion of a boundary between the second rake face and the restraint surface.

Provided is a cutting insert, within which a burr being generated at an outer edge of a finished surface is inhibited and chipping of the cutting insert is inhibited even when the cutting insert is formed to have multiple corners superior in economical efficiency. The cutting insert has an upper surface, a lower surface on an opposite side to the upper surface, and a circumferential side surface connecting the upper surface and the lower surface to each other. A first ridgeline at which the upper surface and the circumferential side surface intersect each other includes major cutting edges and wiper cutting edges which are alternately disposed one by one, and corners each disposed between each of the major cutting edges and each of the wiper cutting edges. A distance between the corners that are adjacent to each other is equal to or less than 60% of a diameter of an inscribed circle of the first ridgeline. The corner that is positioned at one end of the wiper cutting edge is formed at a deburring cutting edge that intersects the wiper cutting edge at an angle smaller than an angle formed by the major cutting edge and the wiper cutting edge. The corner that is positioned at the other end of the wiper cutting edge is formed at a corner cutting edge having a curvature larger than that of the wiper cutting edge.

Chip discharge control is further improved. A cutting insert includes an upper surface, a lower surface, a screw hole having an axis penetrating from the upper surface to the lower surface, a peripheral side surface, and a major cutting edge, a wiper edge, and an inner edge formed in an intersecting region between the upper surface and the peripheral side surface. In a side view in which the peripheral side surface on which the inner edge is formed is seen from a direction perpendicular to the axis, the inner edge includes a recessed part recessed toward the lower surface, a length D.sub.L of the inner edge on one side of the recessed part in the side view is longer than a length D.sub.R of the inner edge on the other side of the recessed part, a lowest point of the inner edge is at a position lower than a flat part of the upper surface, and at least a part of the inner edge on the one side is at a position higher than the flat part of the upper surface. A cutting edge angle φ.sub.23L of the inner edge on the one side of the recessed part is larger than a half of a cutting edge angle φ.sub.23R of the inner edge on the other side of the recessed part.

Cutting tool systems including a cutting tool and cutting inserts are disclosed. The cutting inserts have indexable cutting edges and seating face features which enable uniform facets along a portion of each cutting edge of the indexable insert. The first and second seating face surfaces of the cutting insert each comprise control cavities that adjoin the cutting edge facet surfaces. Each control cavity allows its corresponding cutting edge to have a facet width that is defined by the cavity to provide uniform surfaces. The control cavities reduce and limit the amount of the first and second seating face surfaces that need to be ground. Methods of making such cutting inserts are disclosed.

A cutting insert of a substantially horizontal cylindrical segment shape may include top and bottom surfaces having a circular segment shape. The cutting insert may include a convex side and a flat side. The cutting insert may include a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert may include a hole extending from the convex side towards the flat side. The hole may be positioned at a center of a surface of the flat side.

A reversible cutting insert for milling including opposing and identically or substantially identically top and bottom surfaces interconnected by a continuous peripheral side surface, with a median plane located between the top and bottom surfaces and intersecting the side surface, and an insert axis perpendicular to the median plane about which the cutting insert is indexable. Each top and bottom surface is limited by a circumferential cutting edge intersecting the side surface, the circumferential cutting edge in a top view having the shape of a truncated equilateral triangle. Each circumferential cutting edge includes three analogous sets of cutting edges exhibiting three-fold rotational symmetry about the insert axis. A first cutting edge portion intersects a first support plane.

A cutting insert (10) for a tool (100) for machining a workpiece. The cutting insert (10) is a four-bladed cutting insert which is in the form substantially of a rhomboid. The cutting insert (10) has two identical, oppositely arranged base sides (14a, 14b) and four identical main sides (16a-16d) which extend between the two base sides (14a, 14b). Each of the four main sides (16a-16d) comprises a rectilinear main cutting edge (12a-12d) and a rectilinear secondary cutting edge (26a-26d) which is arranged transversely thereto. The main and secondary cutting edges (12a-12d) and (26a-26d) of each main side (16a-16d) lie in each case in a common cutting plane which is aligned parallel to a contact surface (28a-28d) which is also provided on the main sides (16a-16d).