A coated tool disclosure includes a base body and a coating layer. The coating layer includes crystals having a cubic structure. The coating layer has a striped structure in cross-sectional observation by a transmission electron microscope. The striped structure has two layers alternately located in a thickness direction. The two layers contain Si and at least one metal element. The two layers each contain crystals having the cubic structure. When a lattice constant of a crystal having the cubic structure in one layer of the two layers is referred to as a first lattice constant and a lattice constant of a crystal having a cubic structure in the other layer of the two layers is referred to as a second lattice constant, a difference between a magnitude of the first lattice constant and a magnitude of the second lattice constant is greater than 0% and 0.1% or less.

The present invention provides a lubricant material for assisting machining process comprising a high molecular weight compound (A) having a weight average molecular weight of 5?10.sup.4 or higher and 1?10.sup.6 or lower, a medium molecular weight compound (B) having a weight average molecular weight of 1?10.sup.3 or higher and lower than 5?10.sup.4, and a carbon (C) having an average particle size of 100 ?m or larger.

Provided is a coated cutting tool in which a surface of a substrate is coated with a hard coating film. The hard coating film includes: a layer (A) disposed on the surface of the substrate, and having a face-centered cubic lattice structure, in which the total content ratio of W and Ti is at least 85 atomic %, and which contains W as the most abundant element and Ti as the next most abundant element among metal (including metalloid) elements; and a layer (B) disposed on the layer (A) and having a face-centered cubic lattice structure, which is composed of nitrides or carbonitrides containing Al, Cr, and Si, and in which, among metal (including metalloid) elements, the Al content ratio is at least 50 atomic %, the total content ratio of Al and Cr is at least 85 atomic %, and the Si content ratio is 4 to 15 atomic %.

A surface coated cutting tool comprises: a tool substrate and a coating layer on a surface of the tool substrate; wherein the coating layer comprises a lower layer, an intermediate layer, and an upper layer, in sequence from the tool substrate toward the surface of the tool. The lower layer comprises an A layer having an average composition represented by formula: (Al.sub.1-xCr.sub.x)N, where x is 0.20 to 0.60; the intermediate layer comprises a B layer having an average composition represented by formula: (Al.sub.1-a-bCr.sub.aSi.sub.b)N, where a is 0.20 to 0.60 and b is 0.01 to 0.20; and the upper layer comprises a C layer having an average composition represented by formula: (Ti.sub.1--Si.sub.W.sub.)N where is 0.01 to 0.20 and is 0.01 to 0.10; and the upper layer has a repeated variation in W level with an average interval of 1 nm to 100 nm between adjacent local maxima and minima.

A coated tool include a first surface, a second surface which is adjacent to the first surface, and a cutting edge which is located on at least a portion of a ridge between the first surface and the second surface. The coated tool further includes a substrate, and a coating layer that is located on the substrate. The coating layer includes a titanium carbonitride layer and an aluminum oxide layer which has an -type crystalline structure. The titanium carbonitride layer is located nearer to the substrate than the aluminum oxide layer. When a value represented by the following equation is taken to be an orientation factor Tc(hkl) on the basis of peaks of the aluminum oxide layer analyzed by X-ray diffraction analysis, a ratio (Tcf(104)/Tcf(012)) of orientation factors Tcf(104) to Tcf(012) of the coating layer on the second surface is higher than a ratio (Tcr(104)/Tcr(012)) of orientation factors Tcr(104) and Tcr(012) of the coating layer on the first surface: Tc(hkl)={I(hkl)/I.sub.0(hkl)}/[(1/7){I(HKL)/I.sub.0 (HKL)}].

A hard material layer system with a multilayer structure, comprising alternating layers A and B, with A layers having the composition Me.sub.ApAO.sub.nAN.sub.mA in atomic percent and B layers having the composition Me.sub.BpBO.sub.nBN.sub.mB in atomic percent, where the thermal conductivity of the A layers is greater than the thermal conductivity of the B layers. Me.sub.A and Me.sub.B each comprise at least one metal of the group Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al, p.sub.A indicates the atomic percentage of Me.sub.A and p.sub.B indicates the atomic percentage of Me.sub.B and the following is true: P.sub.A=P.sub.B, n.sub.A indicates the oxygen concentration in the A layers in atomic percent and n.sub.B indicates the oxygen concentration in the B layers in atomic percent and the following is true: n.sub.A<n.sub.B, and m.sub.A indicates the nitrogen concentration in the A layers in atomic percent and m.sub.B indicates the nitrogen concentration in the B layers in atomic percent and the following is true: p.sub.A/(n.sub.A+m.sub.A)=p.sub.B/(n.sub.B+m.sub.B).

There is provided a cutting tool having high wear resistance and fracture resistance by reducing the occurrence of thermal cracking on a cutting edge even during a cutting process of a heat-resistant alloy in which the cutting edge reaches high temperatures. The cutting tool is made from a cemented carbide that is composed mainly of a WC phase and contains 11.5-12.5% by mass of Co and 0.2-0.6% by mass of Cr in terms of Cr.sub.3C.sub.2. The WC phase has a mean particle size of 0.85-1.05 m, an antimagnetic force (Hc) of 13.0-16.0 kA/m, and a Rockwell hardness (HRA) of 89.5-90.5.

A hand drilling tool of one or more elements coupled therebetween comprising: a chuck (2) tightened in the spindle of a tool machine allowing the tool rotation; an elongated point body (3) with tool diameter (2) having at least four helical grooves developing longitudinally on the point body and defining at least two primary cutters, and at least two secondary cutters; said two primary cutters forming a tip angle; said secondary cutters having a discharge surface S; said discharge surface S is shaped so as to create an interruption between the secondary cutters and the primary cutters by contributing to reduce the operator's effort, to reduce the temperature and to promote the discharge of the worked material. Said point body (3) is formed by a substantially cylindrical first portion and a substantially conical second portion with taper towards the end of the tool.

A method for drilling through an assembly forming a stack of at least two different materials uses a drill bit having at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that the end of the drill bit has a projecting conical shape. The first cutting edge is configured to drill a first material. The second cutting edge is made differently from the first cutting edge, to drill a second material. A first rotational drive axis of the drill bit is laterally offset during the drilling by an offset distance D relative to the axis of the drill bit in a direction opposite the first cutting edge when the drill bit is drilling through the first material, and alternately, in a direction opposite the second cutting edge when the drill bit is drilling through the second material.

A rotary cutting tool with an elongate body disposed about a longitudinal axis, the elongate body including a helical flute and a polycrystalline-diamond cutting tip. The cutting tip comprises an inner portion having an inner point angle and an outer portion having an outer point angle different from the inner point angle.