Square-shaped insert for bar-peeling and insert-holder tool for same

A square-shaped bar-peeling insert comprising:

• a first rake surface and a second surface located opposite thereto;
• an insert axis (As) extending through centers of both the first rake surface and the second surface;
• an insert peripheral surface connecting the first rake surface and second surface, the insert peripheral surface comprising first, second, third and fourth peripheral sub-surfaces and first, second, third and fourth corners connecting adjacent peripheral sub-surfaces;
• and
• a first cutting edge extending along an intersection of the insert peripheral surface and the first rake surface, the first cutting edge comprising a sub-cutting edge between each pair of adjacent corners;
• wherein, in a plan view of the first rake surface, each sub-cutting edge comprises:
• a centrally located straight wiper sub-edge;
• and
• first and second peeling sub-edges located on opposite sides of the wiper sub-edge;
• the first peeling sub-edge being at least partially curved and connecting the wiper sub-edge to a first corner edge of a first corner of one of said pairs of adjacent corners;
• the second peeling sub-edge being at least partially curved and connecting the wiper sub-edge to a second corner edge of a second corner of the same pair of adjacent corners as the first corner;
• each of said first and second peeling sub-edges comprising a primary sub-edge connected to said wiper sub-edge and a secondary sub-edge connected at one side thereof to the primary sub-edge and at the other side thereof to said corner;
• in said plan view of the first rake surface:
• the centrally located straight wiper sub-edges define an imaginary square bounding the insert;
• the first, second third and fourth corners are spaced inwardly from the imaginary square;
• sides of the imaginary square have an insert side length SL;
• the wiper sub-edge has a wiper length WL;
• the first peeling sub-edge has a peeling length PL measured parallel to the straight wiper sub-edge;
• the primary sub-edge has a primary length P1L measured parallel to the straight wiper sub-edge;
• the secondary sub-edge has a secondary length P2L measured parallel to the straight wiper sub-edge, with PL=P1L+P2L;
• and
• the primary length P1L is longer than the secondary length P2L.

A double-sided, square-shaped bar-peeling insert comprising:

• a first rake surface and a second surface located opposite thereto;
• an insert axis (As) extending through centers of both the first rake surface and the second surface;
• an insert peripheral surface connecting the first rake surface and second surface, the insert peripheral surface comprising first, second, third and fourth peripheral sub-surfaces and first, second, third and fourth corners connecting adjacent peripheral sub-surfaces;
• and
• a first cutting edge extending along an intersection of the insert peripheral surface and the first rake surface, the first cutting edge comprising a sub-cutting edge between each pair of adjacent corners;
• a second cutting edge extending along an intersection of the insert peripheral surface and the second surface;
• wherein, in a plan view of the first rake surface, each sub-cutting edge comprises:
• a centrally located straight wiper sub-edge;
• and
• first and second peeling sub-edges located on opposite sides of the wiper sub-edge;
• the first peeling sub-edge being at least partially curved and connecting the wiper sub-edge to a first corner edge of a first corner of one of said pairs of adjacent corners;
• the second peeling sub-edge being at least partially curved and connecting the wiper sub-edge to a second corner edge of a second corner of the same pair of adjacent corners as the first corner;
• each of said first and second peeling sub-edges comprising a primary sub-edge connected to said wiper sub-edge and a secondary sub-edge connected at one side thereof to the primary sub-edge and at the other side thereof to said corner;
• in said plan view of the first rake surface:
• the centrally located straight wiper sub-edges define an imaginary square bounding the insert;
• the first, second third and fourth corners are spaced inwardly from the imaginary square;
• each corner lies on a portion of a first circle and each primary sub-edge lies on a portion of a second circle, the first circle having a smaller radius than the second circle,
• sides of the imaginary square have an insert side length SL;
• the wiper sub-edge has a wiper length WL;
• the first peeling sub-edge has a length PL measured parallel to the straight wiper sub-edge;
• the primary sub-edge has primary length P1L measured parallel to the straight wiper sub-edge;
• the secondary sub-edge has a secondary length P2L measured parallel to the straight wiper sub-edge, with PL=P1L+P2L;
• the primary length P1L being longer than the secondary length P2L;
• and
• a lead angle (K) formed between the straight wiper sub-edge and the secondary sub-edge fulfills the condition 15°<K<25°.