Even if chips enter a gap between a flank face and a surface to be worked, the defect of the flank face or a cutting edge is suppressed by the control of the flow of the chips.

A plurality of cutting edges 6, which are undulated in wave forms in a direction of an axis, are formed on an outer periphery of a front end portion of an end mill body 1 rotating about the axis so that phases of the wave forms are displaced from each other in a path of rotation about the axis; flank faces 5 of the cutting edges 6 are covered with a coating film; rough surface regions B and smooth surface regions A are alternately formed on the surface of at least portions of the coating film, which are close to the cutting edges 6, in the direction of the axis; and the number of fine particles or fine protrusions, which have a size in the range of 0.3 µm to 5.0 µm and protrude from the rough surface region B, is larger than that of the smooth surface region A.

A surface-coated cutting tool of the present invention includes a base material and a coating formed on the base material, the coating includes one or two or more layers, a layer among these layers that abuts on the base material is a TiN layer, the TiN layer contains at least one element together with TiN, the element has a concentration distribution in a thickness direction of the TiN layer, and the concentration distribution includes a region where the concentration of the element decreases in a direction from the base material toward a surface of the coating.

A cermet cutting insert has a texture comprising a carbonitride hard phase primarily composed of Ti, a metal binding phase, and incidental impurities,

   wherein the binding phase comprises a Co-Ni-W alloy containing

• tungsten (W) : 15 to 35 percent by weight,
• nickel (Ni) : 10 to 35 percent by weight, and
• cobalt (Co) : 35 to 70 percent by weight,

An insert (1) made of an ultra-high-pressure sintered compact and including no base metal is brazed to a tool body (2) under vacuum by use of a Ti-containing activated silver brazing filler metal (3). This method permits the insert to be securely fixed to the tool body without fear of the insert coming off the tool body even if the tool is a helical one. Because no base metal is needed, the manufacturing yield, efficiency and productivity are improved.

An improved coated hard alloy tool having a substrate made of a hard alloy, and a multi-layer ceramic coating film provided on the surface of the substrate, the coating film including at least one oxide layer. The top several layers of the coating film are missing partially or completely in an area where the tool is brought into frictional contact with a workpiece. At least one oxide layer (such as Al₂O₃ layer) is included in the missing layers. This increases wear resistance of the coated hard alloy tool.