Patent ID: 8465828

Claim:
A surface-coated cutting tool comprising: a substrate; and a covering layer formed on the substrate, wherein the covering layer includes one or two or more sublayers, a thickness T 1 of a portion of the covering layer having the smallest thickness in a cutting edge line portion and a thickness T 2 of the covering layer at a point 1 mm away from a cutting edge line in a rake face direction in a cross section of the surface-coated cutting tool cut by a plane containing a line normal to a surface of the covering layer at the center of a rake face and an edge line at which two flank faces intersect satisfy T 1 <T 2 , and a point a on the surface of the covering layer a distance D a away from the cutting edge line in the rake face direction and a point b on the surface of the covering layer a distance D b away from the cutting edge line in a flank face direction satisfy 0.05 mm ≦D a ≦0.5 mm and 0.01mm ≦D b ≦0.2 mm, and in 10% or more of a region E of the covering layer having a thickness in the range of 0.1T 1 to 0.9T 1 from the surface and extending from the point a to the point b, the deviation in the crystal orientation of crystal grains constituting the covering layer is 5 degrees or more and less than 10 degrees.