Abstract: A square-shaped bar-peeling insert and insert-holder designed with pockets to hold two such square-shaped inserts. Each insert has four peripheral sub-surfaces and corners. Between each adjacent pair of corners is a cutting edge which includes a straight wiper sub-edge and two at least partially curved peeling sub-edges respectively located on opposing sides of the wiper sub-edge. The corners of the insert are inwardly disposed relative to an imaginary square formed by the sub-edges.

Abstract: A turning insert has two opposite main surfaces and a peripheral surface which extends therebetween and has N side surfaces, where 2<N<9. The insert has mirror symmetry about a mid-plane and 360/N degree rotational symmetry about a central axis perpendicular to the mid-plane. The insert has two main edges which each have N main cutting edges and N corner cutting edges. Each main cutting edge has two raised edge portions and a lowered edge portion. Each main surface has N main rake surfaces and N corner rake surfaces. Each main surface further has at least N convex island protrusions and N at least partially convex peninsula protrusions, any and all island protrusions associated with a given main rake surface being located between two adjacent peninsula protrusions, each pair of adjacent peninsula protrusions having at least one island protrusion located therebetween.

Abstract: A square-shaped bar-peeling insert and insert-holder designed with pockets to hold two such square-shaped inserts. Each insert has four peripheral sub-surfaces and corners. Between each adjacent pair of corners is a cutting edge which includes a straight wiper sub-edge and two at least partially curved peeling sub-edges respectively located on opposing sides of the wiper sub-edge. The corners of the insert are inwardly disposed relative to an imaginary square formed by the sub-edges.

Abstract: A turning insert has two opposite main surfaces and a peripheral surface which extends therebetween and has N side surfaces, where 2<N<9. The insert has mirror symmetry about a mid-plane and 360/N degree rotational symmetry about a central axis perpendicular to the mid-plane. The insert has two main edges which each have N main cutting edges and N corner cutting edges. Each main cutting edge has two raised edge portions and a lowered edge portion. Each main surface has N main rake surfaces and N corner rake surfaces. Each main surface further has at least N convex island protrusions and N at least partially convex peninsula protrusions, any and all island protrusions associated with a given main rake surface being located between two adjacent peninsula protrusions, each pair of adjacent peninsula protrusions having at least one island protrusion located therebetween.