A cutting insert and a cutting tool having same are provided. The cutting insert includes an upper surface, a lower surface having a flat surface, side surfaces connecting to each of the upper surface and the lower surface, and cutting edges being formed by the upper surface and the side surfaces. A first cutting edge among the cutting edges is inclined downward. A major side surface among the side surfaces comprises a first major side surface connected to the upper surface so as to constitute the first cutting edge, and a second major side surface connected to the first major side surface and the lower surface. The first major side surface has a reversely positive surface, and the second major side surface has a reversely positive surface or a negative surface, and a minor side surface among the side surfaces has a positive surface or a negative surface.

A cutting insert includes: a polygonal shaped upper surface; a lower surface; a side surface connected to each of the upper and lower surfaces; and an upper cutting edge located at the intersection of the upper surface and the side surface. The upper surface alternately includes three major corners and three minor corners. The upper cutting edge includes: a corner cutting edge; a minor cutting edge inclined toward the lower surface as separating from the corner cutting edge at a first inclination angle; and a major cutting edge inclined toward the lower surface as separating from the minor cutting edge at a second inclination angle. The corner cutting edge, the minor cutting edge and the major cutting edge are located sequentially from a first major corner to each of first and second minor corners, both of which are adjacent to the first major corner.

An end mill includes a plurality of teeth and flutes. The teeth and their associated flutes include one or more correlated physical parameters. One such correlated parameter is that, at an axial location in a front half of an effective cutting length, at least one tooth of the plurality of teeth has a rake angle smaller than an average rake angle value of the plurality of teeth, and, at the same axial location, a flute preceding each such tooth has a helix angle larger than an average helix angle value of the plurality of flutes.

A cutting insert comprises an upper surface including a first corner, and a second and third corner, respectively, adjacent to both sides of the first corner. The upper surface sequentially includes a rake surface along an upper cutting edge, inclined toward a lower surface, going inward from the upper cutting edge at a rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper and lower surfaces, and a connection surface more inward than the rake surface, inclined toward the lower surface, going inward at a connection angle on the basis of the perpendicular plane. An intersecting part of the rake surface and the connection surface includes a highest position in a portion of the intersecting part corresponding to a minor rake surface. A cutting tool with cutting insert, and a method of producing a machined product using the cutting tool are provided.

In a cutting insert according to an embodiment of the present invention, an upper surface sequentially includes a first rake surface and a second rake surface. The first rake surface being inclined toward the lower surface as going inward from the cutting edge at a first rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper surface and a lower surface. The second rake surface is located more inward than the first rake surface and is inclined toward the lower surface at a second rake angle different from the first rake angle on the basis of the perpendicular plane. An intersecting part of the first rake surface and the second rake surface includes a protruded part located at a highest position in a region of the intersecting part along the second side surface. A cutting tool with the cutting insert, and a method of producing a machined product by using the cutting tool are also provided.

A multi-flute ball end mill comprising a shank portion, a cutting edge portion having a ball-shaped tip portion, and 3 or more cutting edges formed in the cutting edge portion; each cutting edge being constituted by a peripheral cutting edge having a twist angle of 35-45, and a ball-end cutting edge having a twist angle at the outermost peripheral point, the twist angle and the twist angle meeting the relation of 7, such that the ball-end cutting edge is smoothly connected to the peripheral cutting edge; the ball-end cutting edge having a radial rake angle of 37 to 11; the peripheral cutting edge having a radial rake angle of 2-8; and a center-lowered, inclined cutting edge integrally extending from a tip end of each ball-end cutting edge to a rotation center point, in a tip end portion of the ball portion near the rotation center point.

An end mill includes a plurality of teeth and flutes. The teeth and their associated flutes include one or more correlated physical parameters. One such correlated parameter is that, at an axial location in a front half of an effective cutting length, at least one tooth of the plurality of teeth has a rake angle smaller than an average rake angle value of the plurality of teeth, and, at the same axial location, a flute preceding each such tooth has a helix angle larger than an average helix angle value of the plurality of flutes.

In a formed end mill, a peripheral cutting edge has a smaller-diameter cutting part and a larger-diameter cutting part. An imaginary line obtained by lining up a deepest point of a flute bottom of a chip discharge flute, which appears in a cross-sectional view perpendicular to an axis of an end mill body, in an extending direction of the chip discharge flute is defined as a virtual flute bottom line. A flute helix angle, which is formed between the virtual flute bottom line and the axis, in a side view when the end mill body is seen from a radial direction orthogonal to the axis, is 0 degrees or more at a distal end part of the chip discharge flute in the axial direction, and increases gradually from the distal end part toward a posterior end in the axial direction.

A cutting insert comprises a first surface sequentially including a first and second inclined surface. The first inclined surface is inclined toward the second surface, going inward from the edge at a first inclined angle on a basis of a perpendicular plane perpendicular to a central axis extending between the first surface and a second surface. The second inclined surface, located more inward than the first inclined surface, is inclined toward the second surface at a second inclined angle different from the first inclined angle on the basis of the perpendicular plane. An intersecting part of the first inclined surface and the second inclined surface includes a first part located at a highest position in a region of the intersecting part along the second side surface. A cutting tool with the cutting insert, and a method of producing a machined product using the cutting tool are provided.

Within examples, systems and methods for forming a hole through at least one layer of a material are provided. An example cutting tool for forming such a hole may include a body, and a first portion of the body having a first diameter and a first radial rake angle. The cutting tool also includes a second portion of the body adjacent the first portion, the second portion having a second diameter and a second radial rake angle, wherein the second diameter is different than the first diameter, and wherein the second radial rake angle is different than the first radial rake angle.