A cemented carbide includes a hard phase and a binder phase, wherein the hard phase has first hard phase grains each composed of tungsten carbide, second hard phase grains including a core portion and a rim portion, a composition of the core portion is represented by M1.sub.x1W.sub.1-x1C.sub.1-y1N.sub.y1, a composition of the rim portion is represented by M2.sub.x2W.sub.1-x2C.sub.1-y2N.sub.y2, each of the M1 and M2 is at least one metal element selected from a group consisting of a group 4 element, a group 5 element in a periodic table, chromium and molybdenum, and the binder phase includes at least one iron group element selected from a group consisting of iron, cobalt and nickel, and a 50% cumulative number grain size of the second hard phase grains is 0.01 ?m or more and 1.0 ?m or less.

A self-locking head-replaceable carbide drill, comprising a cutter head disposed at the upper end of a cutter shank. A cylinder is disposed at the lower part of the cutter head, a vertical cylinder holding slot or cylinder handle holding hole is disposed at the upper end of the cutter bar, at least two cutter head notches are disposed on the drilling body of the cutter head, and each cutter head notch is formed by intersecting a first and a second cutter head contact face. At least two upward protrusions disposed on the wall of the upper end of the cutter bar and have the same number as the cutter head notches. When assembling the cutter head and the cutter shank, the cutter head ridge edges and the inner surfaces of the protrusions are in non-contact fit, interference fit and non-interference fit in sequence.

A cutting tool based on an embodiment of the present invention is provided with a cylindrical main body section which is made of a cobalt-containing cemented carbide alloy and is rotatable about the central axis thereof, a cutting edge which is provided at at least one of the tip and the periphery of the main body section, a chip discharge groove which extends from the cutting edge toward the rear end of the main body section, and a coating layer which is made of diamond and covers the cutting edge, wherein the cobalt content of the surface of the main body section at the part coated with the coating layer is less than the cobalt content of the surface of the main body section at parts other than the part coated with the coating layer.

A cemented carbide including a hard phase, a binding phase, and inevitable impurities. The hard phase satisfies a first hard phase composed mainly of tungsten carbide, and a second hard phase composed mainly of a compound. The compound contains multiple types of metallic elements including tungsten and at least one element selected from carbon, nitrogen, oxygen, and boron. The second hard phase satisfies D10/D90<0.4, wherein D10 denotes a cumulative 10% grain size in an area-based grain size distribution on a surface or cross section of the cemented carbide, and D90 denotes a cumulative 90% grain size in the area-based grain size distribution, and satisfies .sup.2<5.0, wherein .sup.2 denotes the variance of the distance between the centroids of the nearest two of the second hard phases. The average grain size D.sub.W of the first hard phase ranges from 0.8 to 4.0 m and satisfies D.sub.M/D.sub.W<1.0, wherein D.sub.M denotes the average grain size of the second hard phase.

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 vibration damping toolholder for a metal cutting tool, the toolholder including a holder body provided with an internal cavity, which extends inside the holder body along the longitudinal axis, and which has a first cavity end at a first holder body end. The damping toolholder further includes a tuning mass, which is movably arranged inside the cavity and extends along the longitudinal axis, and which has a first tuning mass end at the first holder body end. The damping toolholder also includes a damping medium, which surrounds the tuning mass inside the cavity, and a single primary spring element, which is positioned inside the cavity. An outer spring element end is immovably fixed to a first cavity end at the longitudinal axis, and an inner spring element end is immovably fixed to the first tuning mass end at the longitudinal axis.

A coated cutting tool and a hard and wear resistant coating for a body include at least one metal based nitride layer. The layer is (ZrxCrl-x-y-zAlyMez)Na with 0.55<x<0.85, 0.05<y<0.45, 0z<0.20, 0.95<a<1.10, and Me is one or more of the elements: Y, Ti, V, Nb, Ta, Mo, W, Mn or Si. The layer can have a thickness between 0.5 m and 15 m and be comprisied of a single cubic phase or a single hexagonal phase or a mixture thereof. In an exemplary embodiment, the layer is a cubic phase of a sodium chloride structure. The layer can be deposited using cathodic arc evaporation and is useful for metal cutting applications generating high temperatures.

A rod, a cutting tool and a method for manufacturing a cutting tool are disclosed. In an embodiment, the rod may include a cemented carbide member containing WC and Co. The cemented carbide member may be elongated and include a first end portion and a second end portion in a longitudinal direction. The first end portion may have a Co content Co.sub.AC smaller than a Co content Co.sub.BC of the second end portion. The cemented carbide member may include a first portion on a side of the first end portion and a second portion on a side of the second end portion. The first portion may have a gradient S.sub.1 representing a change in a Co content per milliliter. The second portion may have a gradient S.sub.2 representing a change in a Co content per milliliter. The gradient S.sub.1 may be greater than the gradient S.sub.2.

Provided are a cemented carbide having excellent plastic deformation resistance and a cutting tool in which the cemented carbide is used as a substrate. A cemented carbide includes a hard phase containing tungsten carbide particles and a binder phase containing, as a main component, an iron-group element, wherein the formula B/A0.05 is satisfied, where A represents the number of the tungsten carbide particles, and B represents the number of tungsten carbide particles whose number of contact points with other tungsten carbide particles is 1 or less. Preferably, the iron-group element includes cobalt, and the cobalt content in the cemented carbide is 8% by mass or more. Preferably, the tungsten carbide particles have an average particle diameter of 3 m or more.

A deep hole drill head support pad whose edge chamfers are formed in a continuous grinding operation so that there are no discontinuities in the angled side surface leading up to the outer surface thereof. A method of manufacturing the support pad includes generating a virtual guide metric including a curved travel path for a grinding surface around a support pad blank, and a plurality of control surfaces intersecting with the curved path at separate locations along its length, each control surface defining an angle of orientation of the grinding surface. A CNC grinding machine can interpret the virtual guide metric to change the angle of orientation of a grinding surface relative to a support pad blank as it moves between adjacent control surfaces in a continuous manner.