Patent ID: 9539652
Date: 2017-01-10
CPC Classifications: B23B,B23H,B23P,Y10T

Claim:
1. A rotary cutting tool comprising: an elongate body disposed about a longitudinal axis, the elongate body including a helical flute and a polycrystalline diamond cutting tip having an external radial circumference; the cutting tip comprising: an inner portion comprising: a pair of first cutting edge portions, wherein each first cutting edge portion extends radially away from a central portion of the cutting tip; each of the first cutting edge portions being substantially straight along its entire length when viewed in longitudinal cross-section; wherein an inner point angle is defined between the first cutting edge portions; an outer portion comprising: a pair of second cutting edge portions, wherein each second cutting edge portion extends directly from a corresponding first cutting edge portion toward the external radial circumference; each of the second cutting edge portions being substantially straight along its entire length when viewed in longitudinal cross-section; wherein an outer point angle is defined between the second cutting edge portions, the outer point angle being greater than the inner point angle; and an outer margin on the external radial circumference; wherein the inner point angle is in the range of about 110 degrees to about 140 degrees; and wherein the outer point angle is in the range of more than 150 degrees to less than 180 degrees.