Diamond film cutting tool

A rotary cutting tool comprising a body member having an inner core of base material and an outer surface, said body member being fluted at least along a portion of its length and containing at least one fluted section defining a wedge-shaped section having a rake face ending at a cutting edge at the outer surface of the body member, said wedge-shaped section having a slotted channel disposed therein in the base material and extending parallel to and adjacent to the cutting edge of the body member, said slotted channel containing a chemical vapor deposited diamond film cutter element having a major surface which extends from its position in the slot to the outer surface of the body member to form the cutting edge and has a portion of its major surface exposed near the cutting edge so that said rake face includes a first, diamond film rake face surface segment extending away from the cutting edge and a second, base material rake face surface segment extending generally in a direction away from the cutting edge from the boundary of the first surface segment remote from the cutting edge, the radial rake angle of the second rake face segment being less than the angle between the plane of that portion of the major surface which lies in the channel and underneath the base metal rake face segment and a plane through the rotational axis and said boundary.