A cutting tool includes a shaft portion and a plurality of edge region groups. The ridgeline between the first rake face portion and the first flank face portion constitutes a first cutting edge portion. The ridgeline between the second rake face portion and the second flank face portion constitutes a second cutting edge portion. As seen from the direction perpendicular to a plane tangent to the outer peripheral surface, in a state where the central axis overlaps a first end on the front end side of the first cutting edge portion, the inclination angle of the first cutting edge portion relative to the central axis is larger than the inclination angle of a straight line relative to the central axis, the straight line connecting the first end to a second end on the front end side of the second cutting edge portion.

The present invention relates to a cutting insert applicable to machining tools and the tool bearing it. The insert (1) has a cutting edge (12) which can be completely sharp or can have a rounding between R=0.030 mm and 0.050 mm, with an angle of impact (123) between 68 and 90 in both cases, and a rounded chip breaker (13), both arranged in a layer of polycrystalline diamond (PCD) (11) at least 1 mm thick covering the entire cutting surface of the insert (1).

The tool includes a body (2) formed by a core (22) coupleable to the machining center, said core externally bearing a perimetral sleeve (21) housing the cutting inserts (1), with the layer of PCD (11) thereof being in direct contact with the sleeve (21).

The invention may include a hydraulic system (23) between the sleeve (21) and the core (22).

A diamond tool comprising a tool shank and a tool head, which is fixed on the tool shank and which is formed by a layer of material interspersed with diamonds at least in sections, the layer of material interspersed with diamonds at least in sections being directly integrally bonded to the tool shank by an electroplating deposition process and the tool head having a recess on the front side, so that in cross-section the tool head has the form of a circular ring in the area of the free end, the tool head forming a hollow milling cutter and a wall forming the hollow milling cutter and having the form of a circular ring consisting only of a nickel-diamond material that is grown by electroplating.

The invention relates to a rotary tool (1; 101; 201; 301; 401) for cutting large inside diameters at the outer circumference (2) of which at least one cutting edge (4; 104; 204) is arranged, comprising a support structure (10; 110; 210; 310; 410) which includes a supporting area (14; 114; 214) which indirectly or directly supports the cutting edge (4; 104; 204), and comprising a chucking portion (24; 124; 224; 324; 424) for coupling to a tool holder, wherein the support structure (10; 110; 210; 310; 410) is designed in light-weight construction and the area (14; 114; 214) of the support structure (10; 110; 210; 310; 410) indirectly or directly supporting the cutting edge (4; 104; 204) is limited regarding thermal expansion by a corset structure (12; 112; 212; 312; 412).

A bit for drilling with a casing or liner string includes: a tubular stem made from a high strength metal or alloy; a head: having a cutting face with an inner cone, an outer shoulder, and an intermediate nose between the cone and the shoulder; attached to an end of the stem; and made from a nonferrous metal or alloy; a plurality of blades formed integrally with the head, made from the nonferrous metal or alloy, and each extending from a center of the cutting face to the shoulder; a plurality of superhard cutters mounted along each blade; a plurality of gauge pads formed integrally with the stem; and a flush joint formed between each blade and a respective gauge pad. A yield strength of the high strength metal or alloy is at least twice a yield strength of the nonferrous metal or alloy.

The use of cryogenic coolant in a machining operation in Ti, Ti-alloys or Ni-alloys together with a cutting tool of a cemented carbide substrate with a gradient surface zone with a thickness of between 50-400 m is provided. The cemented carbide substrate has a binder phase gradient with the lowest binder phase content in the outermost part of the gradient surface zone and the cemented carbide having graphite. The arrangement leads to a significantly prolonged tool life.

A shaft portion and a blade portion provided on a side surface of the shaft portion are included, and the blade portion includes cutting blades arranged in a plurality of lines on a side surface of the shaft portion along a peripheral direction, and arranged in a plurality of stages in an extending direction of a shaft center of the shaft portion in each line. Further, the cutting blade has a radial-direction clearance angle, a tip end-side clearance angle, and a base end-side clearance angle.

Provided is a cutter apparatus for machining a difficult-to-machine material, the cutter apparatus including: a cutting tool body which has a fastening portion formed at a center thereof; one or more cutters which are installed on the cutting tool body, and have superhard insert tips fixed to end portions thereof, respectively; and an angle adjusting unit which is installed in an internal space of the cutters, and adjusts angles of the cutters by spreading or retracting the cutters, so that angles of the cutters may be easily adjusted in accordance with a condition for cutting a difficult-to-machine material, in order to prevent damage to the superhard insert tips when machining a difficult-to-machine material having high hardness and high toughness.

A cutting tool includes a shaft portion and a plurality of edge region groups. The ridgeline between the first rake face portion and the first flank face portion constitutes a first cutting edge portion. The ridgeline between the second rake face portion and the second flank face portion constitutes a second cutting edge portion. As seen from the direction perpendicular to a plane tangent to the outer peripheral surface, in a state where the central axis overlaps a first end on the front end side of the first cutting edge portion, the inclination angle of the first cutting edge portion relative to the central axis is larger than the inclination angle of a straight line relative to the central axis, the straight line connecting the first end to a second end on the front end side of the second cutting edge portion.

A corner radius end mill includes a tooth adjacent a helically extending flute. The tooth includes axial and radial relief surfaces connected by a corner relief surface, as well as rake surface having a rake ridge. The rake ridge is continuously curved from a bisector line until at least an axial location rearward of the corner relief surface.