Special boring insert

An indexable, on edge, reversible cutting insert for use with a boring toolhead, comprising:

• a top and bottom face substantially parallel to each other with a sidewall running substantially unbroken therebetween to define a body;
• said sidewall comprised of seating surfaces opposite each other and end wall portions opposite each other;
• said body having rounded corners when viewed from said top or bottom face;
• said top or bottom face having a cutting edge defined by the intersection of the seating surface and the top or bottom face;
• said cutting edge, when viewed from said seating surface, being inclined relative to said top or bottom face from one corner to the opposite corner of the insert body;
• a descending land surface rearward of said cutting edge;
• said descending land surface following said cutting edge;
• and an increasing incident angle surface rearward of said descending land surface which together with said descending land surface defines a chip breaker groove;
• each said increasing incident angle surface extending from said descending land surface to said top or bottom face;
• said descending land surface having a positive rake angle and said increasing incident angle surface having an axial rake angle so as to define a bi-directional chip breaker groove;
• at least two chip breaker grooves being formed on the top and bottom surface opposite each other, said chip breaker grooves forming at least two diagonally opposed cutting corners;
• each said cutting corner comprised of a scalloped radius formed in said incident angle surface which intersects a chip directional flat formed in the groove at an obtuse angle to form a bi-directional pocket area;
• and an aperture centrally located on said seating face and extending through said body to the opposite seating face;
• said central aperture being counterbored.