An indexable drilling tool, includes a cutter body, an outer blade and an inner blade. The inner blade is surrounded by a first upper surface, a first lower surface and a first side surface. The first upper surface intersects with the first side surface to form multiple identical inner cutting edges. When drilling, a cutting area of the inner cutting edge as a main cutting edge is located between a central inner point and a central outer point on the inner cutting edge. In a feed direction, an inner convex cutting portion with a maximum cutting depth is arranged between the central inner point and the central outer point. Distances between the central inner point and the inner convex cutting portion and between the central outer point and the inner convex cutting portion in an axial direction are H1 and H2 respectively, which meets the following requirement: 0.9H2≤H1≤1.1H2.

An indexable cutting tool in which cutting ability can be ensured while suppressing the occurrence of chatter vibration. In outer circumferential blades provided on a tool main body, the axial rake angles are all set to the same angle, and so are the radial rake angles. With this configuration, the cutting ability of an indexable cutting tool can be ensured. Furthermore, the disposing intervals, in the circumferential direction of the tool main body, of the plurality of outer circumferential blades that are provided in, at least, a first groove of a plurality of groove are set to unequal values. With this configuration, it is possible to make the intervals at which the outer circumferential blades adjoining in the axis direction contact a workpiece unequal, suppressing resonance of periodic vibration occurring in cutting and, thus, suppressing the occurrence of chatter vibration.

Proposed in a milling head, which has a plurality of machining milling teeth and tooth gaps arranged therebetween, whereby the milling teeth and the tooth gaps are arranged along a circumferential surface of the milling head, which milling head is to be provided with a number of milling teeth, which is greater than and/or substantially equal to the number of milling teeth ascertained using the equation y=a.Math.x.sup.5+b.Math.x.sup.4+c.Math.x.sup.3+d.Math.x.sup.2+e.Math.x+f, wherein x is the diameter of the milling head in millimeters and y is the tooth pitch, i.e. the distance between two adjacent milling teeth in millimeters, and it substantially applies that the value of a ranges between a=1.7.Math.10.sup.−9 and a=2.3.Math.10.sup.−9, the value of b between b=−5.Math.10.sup.−7 and b=−11.Math.10.sup.−7, the value of c between c=0.7.Math.10.sup.−4 and c=1.3.Math.10.sup.−4, the value of d between d=8.5.Math.10.sup.−3 and d=9.7.Math.10.sup.−3, the value of e between e=2.6.Math.10.sup.−1 and e=3.7.Math.10.sup.−1 and the value of f between f=−1.5.Math.10.sup.−1 and f=−2.6.Math.10.sup.−1.

A variable radius gash geometry may be provided on a variety of rotary cutting tools. The rotary cutting tools extend along a longitudinal axis, from a shank towards a cutting face that engages a material to be cut during a plunge or ramp operation, and a plurality of gashes may be provided in the cutting face of the rotary cutting tool. The gashes may each be a full radius gash, and the radius defining each of the gashes may be unique or different from one another and tangent to an axial rake face and clearance face surrounding the gash.

A milling tool comprising a cylindrical shaft part, which has a central axis and which is followed by a cylindrical cutting part comprising at least three circumferential cutting edges, which run helically and which are separated from one another by chip grooves. The circumferential cutting edges continue via cutting edge corner regions in end cutting edges, which run essentially radially and which subsequently slope away from the milling cutter face towards the central axis from radially outer end cutting edge sections, in each case with a cutting edge section, which is formed by ground-in end pockets. The cutting edge section slopes continuously all the way to the central axis. In the region of the milling cutter core, it is formed by a point thinning, which is introduced into the end pocket and by means of which a center cutting edge is created. Also, a method for producing the milling tool.

An end mill includes a plurality of peripheral cutting edges that are defined by three types of teeth including a right-handed helical tooth that is twisted rightward, a left-handed helical tooth that is twisted leftward, and a curved tooth which is twisted in a direction reversed right and left on a way thereof and which has a curved shape curved in an arcuate or arched manner in a development view of an outer circumferential surface of the end mill around an axis such that a corresponding one of the peripheral cutting edges is provided on a concave side of the curved shape. Each adjacent pair of the peripheral cutting edges adjacent to each other are defined by the respective teeth that are different in type from each other.

An indexable roughing end mill capable of suppressing generation of chattering is provided. When the positions of cutting inserts (40) arranged in each spiral groove (28) are defined as a first segment to an n.sup.th segment (where n is an integer of 2 or higher) from a leading end surface (22) side of a tool body (20) toward a base end surface (21) side, all of the angles (1 . . . m (where m is an integer of 2 or higher)) between lines connecting a rotational axis (O) and the cutting inserts (40) in the first segments of the respective spiral grooves (28) are different from each other, as viewed from the leading end surface side of the tool body (20), and an angle (t) between the cutting insert (40) in the first segment and the cutting insert (40) in the n.sup.th segment (the uppermost segment) in a spiral groove 28 is different from any of the angles 1 . . . m (where m is an integer of 2 or higher) between the lines, as viewed from the leading end surface side of the tool body (20).

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.

An indexable cutting tool in which cutting ability can be ensured while suppressing the occurrence of chatter vibration. In outer circumferential blades provided on a tool main body, the axial rake angles are all set to the same angle, and so are the radial rake angles. With this configuration, the cutting ability of an indexable cutting tool can be ensured. Furthermore, the disposing intervals, in the circumferential direction of the tool main body, of the plurality of outer circumferential blades that are provided in, at least, a first groove of a plurality of groove are set to unequal values. With this configuration, it is possible to make the intervals at which the outer circumferential blades adjoining in the axis direction contact a workpiece unequal, suppressing resonance of periodic vibration occurring in cutting and, thus, suppressing the occurrence of chatter vibration.

A milling cutter having a shank and a cutting head attached to the shank. The cutting head has a plurality of helical teeth, each tooth including a cutting tip, a leading face and a rear face. A flute is defined between the leading face of a trailing tooth, and a rear face of an immediately preceding tooth. A gully of the flute is generally W-shaped in cross section to provide effective chip evacuation. A method for manufacturing the milling cutter with the W-shaped gully of the flute using a split path grinding process is also disclosed.