Patent attributes
A turning tool includes an indexable turning insert with a polygonal basic shape. The turning insert includes opposite top and bottom sides, main clearance surfaces that extend between the sides and adjacent to main cutting edges, and a secondary cutting edge that is formed between each pair of main cutting edges and connects to a secondary clearance surface. Pairs of the main cutting edges approach each other in corners defining corner angles of at least 55° and at most 80°. Each of the main and secondary clearance surfaces define respective clearance angles with respect to an imaginary reference plane perpendicular to the top side, and the clearance angle of the secondary clearance surface is at least 1° greater than the clearance angle of the main clearance surface. In such a way, internal turning is provided for exceptionally small holes having diameters in the range of 12 to 6 millimeters.
