Patent ID: 7625161

Claim:
A cutting insert for a rotary cutting tool, said rotary cutting tool comprising a tool shank having a first end portion and an opposite second end portion, said first end portion being configured to be inserted into a tool holder, said opposite second end portion having a recess for accommodating said cutting insert and a drive surface adjacent said recess, said cutting insert comprising: a body portion having a first end, an opposite second end, and a central axis, the opposite second end of said body portion structured to be inserted into the recess of the opposite second end portion of said tool shank; and a driven surface extending from said body portion generally away from said central axis, said driven surface comprising: a central portion; a first portion of generally planar shape extending away from said central portion in a direction generally toward the first end of said body portion; and a second portion extending away from said central portion in a direction generally transverse to said central axis, wherein said central portion comprises a curved surface transitioning between the first portion and the second portion of said driven surface and wherein a portion of said driven surface is structured to be engaged by a corresponding portion of said drive surface.