Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

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.

Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

A rotary tool according to an aspect includes a body, a flank face positioned at a side of a tip end of the body, a flute extending from the flank face toward a rear end of the body, and a ridge line positioned at an intersection of the flank face and the flute. The ridge line includes a recessed portion recessed toward the rear end of the body, an inner edge extending from the recessed portion toward the tip end of the body, and an outer edge extending from the recessed portion toward an outer periphery of the body. The flute includes a recessed groove extending along the outer edge. The recessed groove is connected to the recessed portion and the outer edge, and is separated from the inner edge.

Provided is a cutting insert in which cutting edges in a plurality of sections can be used, and it is possible to keep chips, which are discharged from a cutting edge in a section that is being used, from damaging an unused cutting edge in an adjacent section. An edge where an upper surface and a peripheral side surface intersect is divided into a plurality of sections AB, BC, CD, and so on. In each of the plurality of section, the section AB, for example, includes one minor cutting edge and one major cutting edge that is longer than the minor cutting edge. The major cutting edge is inclined at an angle α to be away from a lower surface gradually while extending away from the minor cutting edge. A height position of the upper surface in an up-down direction in which the upper surface and the lower surface oppose each other does not change as the upper surface extends toward the attachment hole, or the height position decreases in a direction from the upper surface toward the lower 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 for a milling tool including an upper side having a central surface, a lower side, a peripheral side surface, and a cutting edge formed between the upper side and the peripheral side surface. The cutting edge having a positively inclined main cutting edge projecting at least partly above the central surface. The upper side includes a rake surface extending inside of and along the at least one cutting edge, sloping downward toward the central surface. A plateau, elevated with respect to the central surface and extending along the main cutting edge, is formed inside the rake surface. A transition between the rake surface and the plateau extends at an angle .sub.2 with respect to an upper extension plane, wherein .sub.2>0.

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.

An end mill that facilitates discharge of chips and enables twining of chips to be suppressed is provided. An end mill (10) includes a tool body, a helical flute, an end cutting edge, a flank, and a gash. The gash forms a cutting face of the end cutting edge. The cutting face is formed as a recessed curved surface and the end cutting edge comprised of a ridge between the cutting face and the flank is concavely curved.

A cutting tool (2)in particular a rotary toolis described, having a cutting edge (4) from which a rake face (6) and a clearance face (8) extend, characterized in that a groove (12) is introduced into the clearance face (8) in a region along the cutting edge (4) so that a part of the clearance face (8) is formed as a wear face (14) that extends between the groove (12) and the cutting edge (4) and is bounded by the groove (12) and the cutting edge (4). The groove (12) advantageously limits the wear of the cutting tool (2) in the region of the cutting edge (4) on the wear surface (14), so that overall the frictional forces that occur are kept small and the service life of the cutting tool (2) is extended. Furthermore, a cutting element for a cutting tool (2) as well as a method for manufacturing the cutting tool (2) are described.