Abstract: A surface-coated cutting tool according to the present invention includes a base material and a coating film formed on the base material. The coating film includes at least one TiCN layer. The TiCN layer has a columnar crystal region. The columnar crystal region is characterized by having a composition of TiCxNy (in which 0.65?x/(x+y)?0.90) and having a (422) plane having a plane spacing of 0.8765 ? to 0.8790 ?.

Abstract: A surface-coated cutting tool according to the present invention includes a base material and a coating film formed on the base material. The coating film includes at least one TiCN layer. The TiCN layer has a columnar crystal region. The columnar crystal region is characterized by having a composition of TiCxNy (in which 0.65?x/(x+y) 0.90), having a (422) plane having a plane spacing of 0.8765 ? to 0.8790 ? and having TC (220) showing a maximum value in an orientation index TC (hkl).

Abstract: A surface-coated cutting tool having excellent abrasion resistance and defect resistance is provided. The surface-coated cutting tool includes a substrate and a covering layer, wherein the covering layer includes one or two or more sublayers, a thickness T1 of a portion of the covering layer having the smallest thickness in a cutting edge line portion and a thickness T2 of the covering layer at a point 1 mm away from a cutting edge line in a rake face direction in a cross section cut by a particular plane satisfy T1<T2, and a point a on the surface of the covering layer a distance Da away from the cutting edge line in the rake face direction and a point b on the surface of the covering layer a distance Db away from the cutting edge line in a flank face direction satisfy particularly numerical ranges of Da and Db, and in 10% or more of a region E of the covering layer having a thickness in the range of 0.1 T1 to 0.