Tool and cutting insert for the fine turning of grooves in workpieces

A cutting insert comprising a top side, a bottom side and a peripheral clearance surface extending between the top and bottom sides, a hole extending from the top side to the bottom side for receiving a fastener, the top side having first and second spaced apart convexly arch-shaped cutting edges, the bottom side including stabilizing structure arranged for preventing angular displacement of the insert about an axis of the hole;

• the first and second convex cutting edges being spaced part by a front edge of the insert and disposed, respectively, on opposite sides of a symmetry plane which intersects the front edge and passes through a center line of the hole;
• the insert configured symmetrically about the symmetry plane;
• each of the first and second cutting edges defining a laterally outermost region of the insert spaced farthest from the symmetry plane in a direction perpendicularly thereto;
• each laterally outermost region spaced from a second plane passing though the hole's center perpendicularly to the symmetry plane, such spacing being in a direction toward the front edge;
• wherein the first and second cutting edges converge toward one another in a direction away from the front edge.