Abstract: A cutting insert, used for a milling cutter, which includes two polygonal main surfaces that are opposite each other and a plurality of side faces and whose main surfaces are rake faces, whose side faces are flank faces, and whose ridge lines at positions where the main surfaces and the side faces cross each other are used as cutting edges include two major side surfaces that are opposite each other and a plurality of minor side surfaces that are formed continuously with the major side surfaces. A mounting hole is provided at the two major side surfaces in a direction in which the mounting hole extends therethrough, and areas of the two major side surfaces are greater than those of the main surfaces. The major side surfaces and the minor side surfaces are provided with flutes along entire regions of the cutting edges.

Abstract: An object is to provide a cutting insert for a milling cutter with which efficiency in machining can be increased. The cutting insert includes two polygonal main surfaces facing each other and side surfaces each connected to a corresponding side of each of the main surfaces. The side surfaces include a major side surface through which an attachment hole extends, a first minor side surface perpendicular to the major side surface, and a second minor side surface disposed between the first minor side surface and the major side surface. A ridge between each of the main surfaces and the major side surface forms a major cutting edge, and a ridge between each of the main surfaces and the second minor side surface forms a minor cutting edge. An angle between the major cutting edge and the minor cutting edge is 145° or larger.

Abstract: To reduce burrs that may be formed at a corner portion of a machined surface in a face milling process, there is provided a cutting insert that does not tend to form burrs. A milling cutting insert includes cutting edges provided as ridges each defined by an upper or lower face and a side face that intersect each other, the cutting edges including a flat cutting edge. The cutting edge include a major cutting edge provided between adjacent ones of corner portions, the flat cutting edge provided at the corner portion, and a minor cutting edge provided between the major cutting edge and the flat cutting edge. A surface roughness of a side face that is continuous with the major cutting edge is higher than a surface roughness of a side face that is continuous with the minor cutting edge.

Abstract: A positioning section that positions a cutting edge, used in cutting, at an indexed point is provided at a portion of a round insert towards a bottom surface at a periphery of the round insert. A support seat, provided at a tool body, includes a first seat side surface, a second seat side surface, and a restraining section. The first seat side surface and the second seat side surface contact and support side surfaces of the round insert that are disposed 90 degrees apart from each other. The positioning section is fitted to the restraining section by bumpy portion fitting. Only one restraining section is provided. A second relief portion that is larger than a first relief portion is provided at a corner at a side of the second seat side surface.

Abstract: An object is to provide a cutting insert for milling that has a minor cutting edge for wiping to achieve improved machined surface quality. A minor cutting edge 3 at a corner includes two circular cutting edge portions 3a and 3a joined to major cutting edges 2 on both sides of the corner and a straight cutting edge portion 3b located between the two circular cutting edge portions 3a. The cutting insert satisfies the following conditions: 0.05 TA?L1?0.4 TA, 0.1 L1?L?0.5 L1, and h?15 ?m, where TA is the radius of a circle inscribed inside the major cutting edges 2 as viewed in the thickness direction of the cutting insert, L1 is the length of the minor cutting edge 3 in the longitudinal direction of the straight cutting edge portion 3b, L is the length of the straight cutting edge portion 3b, and h is the height of the minor cutting edge 3.

Abstract: Corner cutting edges (7 and 8) each having a side portion connected to a minor cutting edge and curved in the same direction as that in which the minor cutting edge is curved are formed on opposite sides of the minor cutting edge (6) of an indexable cutting insert for milling including a major cutting edge (5) formed of a ridge formed by an intersection of a rake face and a flank face and the minor cutting edge (6) for finish machining curved in a convex manner when viewed from a direction perpendicular to the flank face, and the minor cutting edge (6) continues to the major cutting edge (5) via the corner cutting edges (7 and 8).

Abstract: The present invention includes a first ridge line positioned at an intersection between a first surface and an upper side section of a side surface along the first surface; and a second ridge line positioned at an intersection between a second surface and a lower side section along the second surface of the side surface. A cutting section is formed at the first ridge line with the first surface forming a rake face. A second cutting section is formed at the second ridge line with the lower side section along the second surface of the side surface forming a rake face. Selective use can be made of the first cutting section and the second cutting section.

Abstract: An indexable drill which has cutting edges formed of a plurality of indexable inserts and which provides stable performance so that the accuracy of entrance hole diameter and exit hole diameter is improved and generation of burrs at the hole exit can be suppressed. Indexable inserts which form a center cutting edge and a peripheral cutting edge are attached to a drill main body at an end thereof. A ratio between a cutting contribution of the center cutting edge and a cutting contribution of the peripheral cutting edge is set such that the cutting contribution of the center cutting edge is larger. The indexable insert is disposed so at to project forward in the axial direction from the indexable insert so that an outer-end corner of the peripheral cutting edge engages a workpiece first.

Abstract: An indexable insert with nicks for a rotary tool includes plurality of nicks are provided in an upper surface serving as a flank face. The nicks have their ends in the upper surface. The nicks divide a ridge line serving as a main cutting edge in a longitudinal direction. Each nick has a width gradually increasing toward the end.

Abstract: An object is to provide an indexable drill which has cutting edges formed of a plurality of indexable inserts and which provides stable performance so that the accuracy of entrance hole diameter and exit hole diameter is improved and generation of burrs at the hole exit can be suppressed. Indexable inserts 5-1 and 5-2 which form a center cutting edge 8 and a peripheral cutting edge 9 are attached to a drill main body 1 at an end thereof. A ratio between a cutting contribution A of the center cutting edge 8 and a cutting contribution B of the peripheral cutting edge 9 is set such that the cutting contribution A of the center cutting edge is larger. The indexable insert 5-2 is disposed so at to project forward in the axial direction from the indexable insert 5-1 so that an outer-end corner 9a of the peripheral cutting edge 9 engages a workpiece first.

Abstract: An indexable insert with nicks for a rotary tool includes plurality of nicks are provided in an upper surface serving as a flank face. The nicks have their ends in the upper surface. The nicks divide a ridge line serving as a main cutting edge in a longitudinal direction. Each nick has a width gradually increasing toward the end.

Abstract: A replaceable-blade cutting insert for corner milling cutters has a first and second surface; a third and fourth surface connected to a first side edge and a second side edge thereof respectively; and a fifth and sixth surface connected to a first edge and a second edge of the first surface and the second surface respectively. The first surface is used as rake face, the third surface is used as an outer perimeter flank face, and the fifth surface is used as a forward flank face. A twisted surface is disposed on a section of the third surface, forming a ridge line that acts as a main cutting edge intersecting with the first surface and interposed between the third and first surface. The first and second surface can be positioned with a height offset relative to each other so that at least one set of diagonal corners are projected.

Abstract: A replaceable-blade cutting insert for corner milling cutters has a first and second surface; a third and fourth surface connected to a first side edge and a second side edge thereof respectively; and a fifth and sixth surface connected to a first edge and a second edge of the first surface and the second surface respectively. The first surface is used as rake face, the third surface is used as an outer perimeter flank face, and the fifth surface is used as a forward flank face. A twisted surface is disposed on a section of the third surface, forming a ridge line that acts as a main cutting edge intersecting with the first surface and interposed between the third and first surface. The first and second surface can be positioned with a height offset relative to each other so that at least one set of diagonal corners are projected.

Abstract: The present invention includes a first ridge line positioned at an intersection between a first surface and an upper side section of a side surface along the first surface; and a second ridge line positioned at an intersection between a second surface and a lower side section along the second surface of the side surface. A cutting section is formed at the first ridge line with the first surface forming a rake face. A second cutting section is formed at the second ridge line with the lower side section along the second surface of the side surface forming a rake face. Selective use can be made of the first cutting section and the second cutting section.

Abstract: A substantially square throwaway insert can be used for perpendicular machining if a cutting tool on which the insert is mounted is rotated in either direction. All its four corners can be used as cutting edges. Each cutting edge protrudes outwardly toward the center thereof, as viewed from top of the insert. Also, each cutting edge recedes toward the center as viewed from side of the insert. The insert is mounted on a cutting tool with such an axial rake and a radial rake that each corner of the insert can machine a surface having substantially a right angle.