A tool includes, at least on its edge, a sintered cBN compact which includes cBN particles and a bonding phase, a plurality of flutes is formed on a rake face, each of the flutes having a starting end on the edge ridgeline and causing the edge ridgeline to be wavy, and the terminal end of the flute is disposed inwardly of the edge ridgeline. It is preferable that the flute width of the flute decreases with distance from the edge ridgeline, the flute depth of the flute decreases with distance from the edge ridgeline, and the rake face has a positive rake angle.

A method of making a construction comprising a polycrystalline super-hard structure joined to a side surface of an elongate substrate. The method includes: providing a vessel configured for an ultra-high pressure, high temperature furnace, the vessel having an elongate cavity for containing a pre-sinter assembly and defining a longitudinal axis, the cavity having opposite ends connected by a cavity wall. The pre-sinter assembly comprises the substrate, an aggregation comprising a plurality of super-hard grains arranged over at least a part of the side surface of the substrate, and a spacer structure configured for spacing the substrate apart from the cavity wall. The spacer structure comprises material having a Young's modulus of at least 300 GPa. The method further includes inserting the pre-sinter assembly into the cavity, the substrate being substantially longitudinally aligned and the spacer structure arranged between the side surface of the substrate and the cavity wall; applying a force to the pre-sinter assembly and heating it to a temperature, the force being sufficient to generate a pressure within the vessel for sintering the aggregation at the temperature, and providing the construction.

A micro end mill includes a shank made of a first material and a cutting tip made of a second, different material that is bonded to the shank. The first material can be, for example, carbide or high speed steel (HSS), and the second material can be, for example, cubic boron nitride (CBN), polycrystalline cubic boron nitride (PCBN), ceramic or polycrystalline diamond (PCD). The micro end mill is manufactured by producing a billet made of Superhard material using laser radiation, bonding the billet to a shank of the end mill, and removing material from the billet using laser radiation to produce a cutting tip made of the Superhard material. The laser radiation may comprise a laser beam encased in a water jet or a laser beam with a non-Gaussian intensity profile.

A milling tool is disclosed. The milling tool may include an elongated body having a longitudinal axis and a plurality of cutting inserts. The cutting inserts may each have a cutting edge and a cutting radius and be coupled to the body and spaced along the longitudinal axis. One or more of the plurality of cutting inserts may be adjustable (e.g., mechanically adjustable) between first and second cutting radii. A difference between the first and second cutting radii may be at least 10 m. The milling tool may include cutting inserts having a plurality of different cutting radii. The milling tool may be configured to have a length that spans an entire height of an engine bore. The cutting inserts having different radii may compensate for dimensional errors in an engine bore diameter that occur when milling a deep pocket.

Milling tools configured to increase surface roughness are disclosed. The tool may include an elongated body having a longitudinal axis and a plurality of cutting inserts coupled to the body and spaced along the longitudinal axis, each cutting insert having a cutting edge. In one embodiment, the cutting edges may have an orientation that is oblique to the longitudinal axis of the elongated body. Each cutting edge may have a first end having a greater cutting radius than a second end. The cutting edges may be offset from the longitudinal axis of the elongated body by an offset angle. In another embodiment, the cutting edges may have a textured or rough surface profile. For example, the cutting edges may have a mean roughness (Rz) of at least 7.5 m. The milling tools may increase the surface roughness of a milled engine bore to facilitate a subsequent rough honing process.

Cutting insert with a cuboid body has a substantially square top face and bottom face, said top face and bottom face connected by four peripheral adjoining side surfaces. At least two cutting edges are formed at the transition of the top face to at least two side surfaces, that cutting edges defining a plane of the top face. To provide a cutting insert and a corresponding tool suited to produce valve seat surfaces with high precision but still having a rather simple construction and being precisely mountable with ease and less efforts of adjustment, the plane defined by the top face cutting edges of the cutting insert has maximum dimensions of 7 mm7 mm, where the bottom face has a supporting surface formed exactly parallel to the plane defined by the top face cutting edges by means of grinding within a tolerance of less than 5 angular minutes.

Herein is provided a method of milling a brittle workpiece (46) using a milling tool (10), the workpiece (46) comprising a material, the material having a Ductile-Brittle Transition Undeformed Chip Thickness, DBh.sub.rn, the milling tool (10) comprising a tool shank (12) having an axis of rotation (14), and further comprising a tool head (16) comprising superhard material at one end thereof, the tool head (16) having a diameter (42), and operating the milling tool (10) such that an Undeformed Chip Thickness, h.sub.m, of the workpiece (46) is less than said Ductile-Brittle Transition Undeformed Chip Thickness, DBh.sub.m of the material.

A cutting tool for performing cutting operations on a workpiece when the cutting tool is rotated about a central axis by a machine tool, the cutting tool includes a generally cylindrical body disposed about the central axis. The generally cylindrical body includes a first end and an opposite second end. The cutting tool further includes a cutting portion and a mounting portion. The cutting portion is disposed at or about the first end of the generally cylindrical body and includes a number of cutting edges structured to engage the workpiece during cutting operations. The mounting portion is disposed at or about the opposite second end of the generally cylindrical body and is structured to be coupled to the machine tool. At least a portion of the generally cylindrical body comprises a molded portion formed via a molding process about the cutting portion in a manner that couples the cutting portion to the generally cylindrical body.

Methods of fly-cutting a workpiece are disclosed, and in methods in which the position of a fly-cutting head or its associated cutting element is known as a function of time. Also disclosed are methods of forming features, such as grooves or groove segments, in a workpiece such as a cylindrical roll. The features may be provided according to one or more disclosed patterns. Articles made using tools machined in the manner described are also provided, such as polymeric film or sheeting that exhibit certain beneficial properties.

A green body is provided. The green body is made of a superhard material, is used for being fixed on a matrix so as to be machined into a cutting edge part of a cutter. The green body includes a first side surface and a second side surface. Both the first side surface and the second side surface twist at a set helical angle. After being fixed to the matrix, the green body is machined into an edge part for cutting, such as a main cutting edge and a center cutting edge located on the green body made of a same superhard material. The green body is applied to machining the cutting edge of the cutter. A rotating center has a continuous and intact center cutting edge formed by a superhard material.