Rotatable cutting tool with cutting insert and bolster

A rotatable cutting tool having a longitudinal axis and defining an axial direction parallel to the longitudinal axis, comprising:

• a cutting tool body, the cutting tool body having an axial forward end and an axial rearward end, a head portion axially rearward of the axial forward end, a collar portion axially rearward of the head portion, and a shank portion axially rearward of the collar portion and axially forward of the axial rearward end;
• a bolster at least partially received in the head portion, the bolster including a convex-shaped head portion formed with a radius, R1, a collar portion and a tapered shank portion, the convex-shaped head portion including a socket formed with a side wall, a bottom wall, and a radius blend formed with a radius, R2, extending between the side wall and the bottom wall;
• and
• a cutting insert at least partially received in the socket of the bolster, the cutting insert including a convex-shaped conical head portion, a collar portion and an axially-rearward portion, the axially-rearward portion including a forward cylindrical section proximate the collar portion, a radius blend formed with a radius, R5, and a rearward section,
• wherein between sixty percent and ninety percent of the cutting insert is received in the socket of the bolster, thereby reducing forces and stresses transmitted to the cutting tool during a machining operation;
• wherein the cutting insert comprises a super hard material bonded to a cemented metal carbide substrate;
• wherein the super hard material is bonded only to the convex-shaped conical head portion and the collar portion of the cutting insert;
• and
• the collar portion is at least partially received within the socket of the bolster and the axially rearward portion of the cutting insert is received within the socket of the bolster.