CUTTING TOOL

PURPOSE:To make the size of a rigid sintered body by setting the shape of the back surface of the sintered body to protrude toward the nose radius when it is seen on the side of a tool rake face. CONSTITUTION:A back surface 4 of a composite rigid sintered body consisting of a rigid sintered body 1 and a base 2 fixed to its underside surface is recessed like an arc, and this small member is installed to a recess part 6 provided suitably at a corner part of a tool main body 5 by brazing a bottom surface 3 and the back surface 4. For cutting a quenched blade, among illustrated three component forces of cutting 3, that is a main component force Fc, a feed component force Ft, and a back component force Fo, Fo is increased as the tool is abraded to be the biggest. In this case, the back surface 4 of the sintered body 1 has an angle to the feed component force, and a motion of the sintered body 1 to remove is prevented for this angle mechanically as well. In addition, the back component force Fo presses the back surface 4 of the sintered body 1 to the tool main body 5, so it becomes necessary that the component force Ft acting to the part of the surface 4 gets over Fo for removing the sintered body 1 off the main body 5 by the feed component force Ft, thereby resistance to the feed component force becomes very strong.