CUTTING INSERT AND CUTTING TOOL

To provide a cutting insert and a cutting tool that can achieve both cost reduction and flatness of a seating surface by eliminating a grinding step for a lower surface including the seating surface when applied to a cutting insert of one surface.SOLUTION: A cutting insert 1 is a plate-like cutting insert 1 having a center line O, which comprises: an upper surface 2 constituting one of surfaces opposite to each other along the center line O in an axial direction; a lower surface 3 constituting the other of the surfaces opposite to each other; a side surface 4 that connects the upper surface 2 and the lower surface 3 in the axial direction; and a fitting hole 6 formed through in the axial direction. The side surface 4 inclines to extend inside in a radial direction perpendicular to the center line O from the upper surface 2 to the lower surface 3 in the axial direction. The lower surface 3 has a seating surface 3a having a flat surface perpendicular to the center line O, and a pedestal 3b having a projected part projected on the outer peripheral edge of the seating surface 3a so as to be away more from the upper surface than the seating surface 3a in the axial direction. A top 3bc of the projected part of the pedestal 3b is perpendicular to the center line O.SELECTED DRAWING: Figure 2 【課題】片面の切削インサートに適用した場合に、着座面を含む下面に対する研削工程を無くすことにより、コスト削減と着座面の平坦性確保の両方を実現することが可能な切削インサート及び切削工具を提供する。【解決手段】切削インサート１は、中心線Ｏを有する板状の切削インサート１であって、中心線Ｏに沿う軸方向で互いに対向する一方の面を構成する上面２と、互いに対向する他方の面を構成する下面３と、上面２と下面３とを軸方向に繋ぐ側面４と、軸方向に貫通する取付孔６と、を有し、側面４は、軸方向の上面２から下面３へ向かうに従い、中心線Ｏに垂直な径方向の内側へ向けて傾斜して延び、下面３は、中心線Ｏに垂直な平面を有する着座面３ａと、着座面３ａの外周縁に軸方向で着座面３ａよりも上面から離れる方向に突出した突出部を有する台座３ｂと、を有し、台座３ｂの突出部の頂部３ｂｃは中心線Ｏに垂直である。【選択図】図２