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.

An end mill having a plurality of cutting edges on a surface of a rod-shaped main body is rotated about its longitudinal axis and is moved relative to a workpiece in a feed direction tangential and orthogonal to the longitudinal axis along the workpiece. The end mill is also moved relative to the workpiece in a reciprocal manner in the axial direction while it is moved in the feed direction. In this way, a plurality of dimples are formed by the end mill on the workpiece, such that the dimples are relatively spaced apart from each other on the workpiece. The plurality of dimples are arranged side by side in the feed direction along a line inclined at a predetermined angle relative to the feed direction so as to be offset while partially overlapping with respect to each other in the axial direction.

An end mill having a plurality of cutting edges on a surface of a rod-shaped main body is rotated about its longitudinal axis and is moved relative to a workpiece in a feed direction tangential and orthogonal to the longitudinal axis along the workpiece. The end mill is also moved relative to the workpiece in a reciprocal manner in the axial direction while it is moved in the feed direction. In this way, a plurality of dimples are formed by the end mill on the workpiece, such that the dimples are relatively spaced apart from each other on the workpiece. The plurality of dimples are arranged side by side in the feed direction along a line inclined at a predetermined angle relative to the feed direction so as to be offset while partially overlapping with respect to each other in the axial direction.

A plurality of dimples are formed on a processing surface of a workpiece. An aspect ratio of each dimple is greater than or equal to 5.0 and less than or equal to 50.0. The aspect ratio is a ratio of a length of the dimple measured in a longitudinal direction to a lateral width of the dimple measured in a direction perpendicular to the longitudinal direction.

A plurality of dimples are formed on a processing surface of a workpiece. An aspect ratio of each dimple is greater than or equal to 5.0 and less than or equal to 50.0. The aspect ratio is a ratio of a length of the dimple measured in a longitudinal direction to a lateral width of the dimple measured in a direction perpendicular to the longitudinal direction.

A turbine rotor includes a rotor body and a balancing weight slot defined in an exterior circumference of the body. The balancing weight slot has a first axial width and a first radially outward facing surface at a first radial distance from a rotor axis. The rotor also includes a balancing weight entry port defined in a portion of the exterior circumference of the rotor body and aligned with the balancing weight slot. The balancing weight entry port has a second axial width greater than the first axial width and a second radially outward facing surface at a second radial distance from the axis of the rotor body that is smaller than the first radial distance. A method may include machining the entry port into the rotor with a tool. The method may be applied to a new rotor, or to remove cracks initiating from a previous entry port.

A turbine rotor includes a rotor body and a balancing weight slot defined in an exterior circumference of the body. The balancing weight slot has a first axial width and a first radially outward facing surface at a first radial distance from a rotor axis. The rotor also includes a balancing weight entry port defined in a portion of the exterior circumference of the rotor body and aligned with the balancing weight slot. The balancing weight entry port has a second axial width greater than the first axial width and a second radially outward facing surface at a second radial distance from the axis of the rotor body that is smaller than the first radial distance. A method may include machining the entry port into the rotor with a tool. The method may be applied to a new rotor, or to remove cracks initiating from a previous entry port.

A T-shaped tool is configured by fastening a head having cutting blades to a cylindrical shank, the shank is made of cemented carbide and has a tapered male thread formed at a tip end portion thereof, the tapered male thread becomes smaller in diameter toward the tip end, and the head is made of steel and has a tapered female thread formed therein, and the tapered female thread comes into engagement with the tapered male thread.

A T-shaped tool is configured by fastening a head having cutting blades to a cylindrical shank, the shank is made of cemented carbide and has a tapered male thread formed at a tip end portion thereof, the tapered male thread becomes smaller in diameter toward the tip end, and the head is made of steel and has a tapered female thread formed therein, and the tapered female thread comes into engagement with the tapered male thread.

A tip dressing cutter (1) includes a rotary holder (5) and a cutter plate (2). The cutter plate (2) includes a cutting blade portion (2d) formed on a continuous portion of a rake face (2a) and a flank face (2b) and extending along a direction intersecting with a rotation axis (C1). A plurality of recessed grooves (2e) are formed on the flank face (2b), the plurality of recessed grooves (2e) extending from a location proximate to the cutting blade portion (2d) in a circumferential direction around the rotation axis C1 away from the cutting blade portion (2d) and being spaced at predetermined intervals along a direction intersecting with the rotation axis (C1).