摘要 |
A cutting tool insert having a controlled contact clearance behind the cutting edge which limits flank wear and allows more coolant near the cutting edge further allowing an increase in surface speed, feed rates, and tool life. The controlled contact clearance surface provides a first wear zone and a second wear zone, the first wear zone generated during operation of the drill insert allows the flank wear distance to grow from zero to the distance from the cutting edge to the controlled contact clearance surface, the second wear zone keeps the flank wear distance substantially constant until the controlled contact clearance surface is substantially worn away. |