A surface-coated cutting tool includes a substrate and a coating that is disposed on the substrate and formed so as to cover at least a portion of a flank face, in which the coating includes an inner layer and an outer layer formed on the inner layer, the inner layer is formed of at least one layer and includes an aluminum oxide layer as a layer in contact with the outer layer, the outer layer has a multilayer structure that includes three or more layers stacked on top of one another, and each of the layers that constitute the multilayer structure contains titanium.

A surface-coated cutting tool includes a substrate and a coating that is disposed on the substrate and formed so as to cover at least a portion of a flank face, in which the coating includes an inner layer and an outer layer formed on the inner layer, the inner layer is formed of at least one layer and includes an aluminum oxide layer as a layer in contact with the outer layer, the outer layer has a multilayer structure that includes three or more layers stacked on top of one another, and each of the layers that constitute the multilayer structure contains titanium.

A cutting tool includes a substrate and a coating film provided on the substrate, wherein the substrate is a cBN sintered material including more than or equal to 30 volume % and less than 80 volume % of cBN and a binder, the coating film includes a compound layer constituted of a composition of Ti.sub.1-xAl.sub.xC.sub.1-aN.sub.a, where 0.70X0.95 and 0<a1, and the compound layer has a NaCl type crystal structure in a whole or part of the compound layer.

A surface-coated cutting tool includes a base material and a coating formed on the base material. The base material is a cemented carbide or a cermet. A surface of the base material includes a rake face, a flank face, and a cutting edge face connecting the rake face to the flank face. The base material has an oxygen concentration of less than or equal to 1 at. % at a depth position of 0.4 m from the cutting edge face. The coating includes a hard layer. A topmost layer in the hard layer has a compressive stress of more than or equal to 1.5 GPa in absolute value.

A cutting tool includes a base material. The base material is a cemented carbide or a cermet. A surface of the base material includes a rake face, a flank face, and a cutting edge face connecting the rake face to the flank face. The base material has an oxygen concentration of less than or equal to 1 at. % at a depth position of 0.4 m from the cutting edge face.

A cutting tool includes a base material. The base material is a cemented carbide or a cermet. A surface of the base material includes a rake face, a flank face, and a cutting edge face connecting the rake face to the flank face. The base material has an oxygen concentration of less than or equal to 1 at. % at a depth position of 0.4 m from the cutting edge face.

A pipe-tapered-thread machining tap has a thread, four spiral flutes and four cutting edges that include a plurality of thread intersection portions at each of which a corresponding one of the four cutting edges intersects with the thread. The thread intersection portions of the cutting edges have four groups, such that each of the four groups has ones of the thread intersection portions that are portions of a corresponding one of the four cutting edges. Every two of the thread intersection portions of each of the four groups is removed, such that, in each of the four groups, at least one of the thread intersection portions that is removed and at least another one of the thread intersection portions that is not removed are alternately arranged in a direction in which a corresponding one of the four cutting edges extends.

A pipe-tapered-thread machining tap has a thread, four spiral flutes and four cutting edges that include a plurality of thread intersection portions at each of which a corresponding one of the four cutting edges intersects with the thread. The thread intersection portions of the cutting edges have four groups, such that each of the four groups has ones of the thread intersection portions that are portions of a corresponding one of the four cutting edges. Every two of the thread intersection portions of each of the four groups is removed, such that, in each of the four groups, at least one of the thread intersection portions that is removed and at least another one of the thread intersection portions that is not removed are alternately arranged in a direction in which a corresponding one of the four cutting edges extends.

Embodiments of the invention relate to methods of making articles having portions of polycrystalline diamond bonded to a surface of a substrate and polycrystalline diamond compacts made using the same. In an embodiment, a molding technique is disclosed for forming cutting tools comprising polycrystalline diamond portions bonded to the outer surface of a substrate.

A device and method for broken tap removal are provided herein. The tap includes a circular longitudinal cavity used for removal and coolant transport. A tap removal tool that is pre-formed to fit the tap's center hole and provides at least three points of contact with the broken tap portion to allow for ease in removing the broken tap.