Tool bits

Claim 1

A THROWAWAY INSERT TOOL BIT FOR USE WITH A HOLDER, SAID BIT BEING FORMED WITH TWO CLOSELY SPACED OPPOSITE SUBSTANTIALLY PARALLEL PLANE FACES AND A SIDE SURFACE AT RIGHT ANGLES TO THE PLANES OF SAID FACES PRESENTING A CUTTING EDGE ON EACH FACE, A RELATIVELY NARROW GROOVE OF UNIFORM WIDTH IN EACH FACE ALONG EACH CUTTING EDGE PARALLEL THERETO HAVING AN OUTWARDLY TAPERED SURFACE TERMINATING IN AN EFFECTIVE POSITIVE RAKE SHARP CUTTING EDGE AT A PREDETERMINED SUBSTANTIALLY CONSTANT ACUTE ANGLE ALONG SUBSTANTIALLY THE LENGTH OF THE CUTTING EDGE AT THE INTERSECTION OF THE PLANE OF THE RESPECTIVE ONE OF SAID FACES WITH SAID SIDE SURFACE AND IN AN INWARDLY CURVED SURFACE EXTENDING TO SAID ONE OF SAID FACES ADAPTED TO FORM A CHIP CURLING AND BREAKING SURFACE INWARDLY SPACED FROM AND CLOSELY ADJACENT TO SAID RESPECTIVE CUTTING EDGE, SAID TWO OPPOSITE PARALLEL FACES EACH HAVING A RELATIVELY LARGE PLANE CENTRAL PORTION PROVIDING A TOOL HOLDER SUPPORT AND CLAMP ENGAGING SURFACE INSIDE SAID RELATIVELY NARROW GROOVES.