A coated cutting tool includes a substrate and a coating layer formed onto the surface of the substrate. The coating layer contains an -type aluminum oxide layer. A residual stress value at the (116) plane of the -type aluminum oxide layer is greater than 0. A residual stress value at the (012) plane of the -type aluminum oxide layer is smaller than 0.

According to one implementation, a drill that drills at least one of a composite material and a metal is provided. A web thickness at least at a tip of the drill is not less than 5% and less than 25% of at least one diameter of the drill. Further, according to one implementation, a method of manufacturing a drilled product is provided. The drilled product is manufactured by drilling a workpiece using the above-mentioned drill. The workpiece is made of the at least one of the composite material and the metal.

A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The coating has a layer of -Al.sub.2O.sub.3, wherein the -Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)7.2 and wherein the ratio of I(0 0 12)/I(0 1 14) is 1.

A cutting tool made by an additive manufacturing process is disclosed. The cutting tool has an exterior surface and an enclosed interior cavity defined by one or more inwardly facing surfaces. The interior cavity may have internal supports such as a lattice or a honeycomb structure. The cutting tool may be an insert, drill or endmill with coolant holes.

A surface-coated cutting tool includes a base material and a coating formed on a surface of the base material. The coating includes a first hard coating layer including crystal grains having a sodium chloride-type crystal structure. The crystal grain has a layered structure in which a first layer composed of nitride or carbonitride of Al.sub.xTi.sub.1-x and a second layer composed of nitride or carbonitride of Al.sub.yTi.sub.1-y are stacked alternately into one or more layers. The first layer each has an atomic ratio x of Al varying in a range of 0.76 or more to less than 1. The second layer each has an atomic ratio y of Al varying in a range of 0.45 or more to less than 0.76. The largest value of difference between the atomic ratio x and the atomic ratio y is 0.05x-y0.5.

A coated cutting tool includes a substrate and a coating having at least one ?-type aluminum oxide layer. In a cross-section of the ?-type aluminum oxide layer, when an angle formed by a normal to the cross-sectional surface and a normal to a (222) plane of a particle of the ?-type aluminum oxide layer is regarded as a misorientation, and when areas of particles, each of which has a misorientation ranging from 0-90 degrees, of the ?-type aluminum oxide layer are defined as constituting 100 area %, and the areas of particles, each of which has a misorientation ranging from 0-90 degrees, of the ?-type aluminum oxide layer are divided into respective 10-degree pitches, a total Sa of the areas of particles having a misorientation ranging from 20-30 degrees, of the ?-type aluminum oxide layer is at a maximum from among totals of areas for nine divisions in respective 10-degree pitches.

A method for machining ribs or grooves on a shaft (7) with an axial bearing (24) forming part of the shaft. The ribs or grooves (32, 24a) are obtained on a workpiece portion of the shaft and of the axial bearing, by moving the shaft or at least one tool holder fitted with a machining tool in a longitudinal direction of machining, by the tool performing reciprocating motions with a position in contact and with a position not in contact with the shaft or the axial bearing from the beginning to the end of the workpiece portion or face. The reciprocating motions are synchronised with the sinusoidal programming carried out in the machining unit, along with the desired and programmed arrangement of the ribs or grooves to be produced.

A method for machining ribs or grooves on a workpiece including a shaft (7) and an air or gas axial bearing (24) attached to the shaft or forming a part of the shaft. The workpiece is rotated about a longitudinal axis of a centrifugal compressor. All of the ribs or grooves are obtained at once by the machining tool on a workpiece portion driven such that it rotates, by moving the workpiece or the tool holder in a longitudinal direction, the machining tool moving back and forth with a machining position in contact with the workpiece and a position wherein it is not in contact with the workpiece from the beginning to the end of the workpiece portion. Reciprocating motions of the machining tool are synchronised with the sinusoidal program, as well as with the desired, programmed arrangement of the ribs or grooves to be produced on the workpiece portion.

A component obtainable by a process which includes providing a composition and sintering the composition at a sintering temperature of from 1250 C. to 1400 C. for a period of from 3 to 15 minutes. The composition includes hard material particles with an inner core of fused tungsten carbide and an outer shell of tungsten carbide, and a binder metal selected from Co, Ni, Fe and alloys with at least one metal selected from Co, Ni and Fe.

The cutting tool (1), especially drill or milling cutter, comprises a base (3) which extends in an axial direction (2) and has an outer shell (14) with at least one interior recess (18) that extends in the axial direction (2), a supporting structure (16) having at least one separating piece (26) which separates a plurality of recesses (18) from each other being formed in the supporting structure. The cutting tool (1) is particularly a solid hard-metal tool. The supporting structure (16) ensures an efficient use of material.