The throwaway insert includes a base and a cutting edge member. The cutting edge member includes a rake face, a flank face, a first connecting face, a second connecting face, and a first ridgeline serving as a cutting edge. The rake face includes a main surface and a first chamfer provided at an edge tip portion of the cutting edge member, the edge tip portion including an extreme tip portion of the cutting edge member. In a plan view from an upper surface of the base, the flank face, the first connecting face, and the second connecting face are located external to the base. The first chamfer is inclined relative to the main surface so as to increase a thickness of the cutting edge member as the first chamfer is closer to the main surface.

A method for manufacturing a cubic boron nitride cutting tool including a base metal and sintered cubic boron nitride compact at a corner portion of the base metal, capable of improving the accuracy of the center height and reducing the angle of inclination or width of a negative rake face; and the cubic boron nitride cutting tool. The method includes grinding the compact by pressing it against an end face of a grindstone of a grinder to form flank and rake faces on the compact while the base metal of the cutting tool is held by a chuck of the grinder, so that the compact is substantially ground. The rake face is formed to be recessed from a top face of the base metal or only a portion of the compact that protrudes from a base-metal rake face is ground while the tool is continuously held by the chuck.

cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.

cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.