Abstract: A hollow milling tool which is adjustable through a wide range of cutting diameters while maintaining a constant radial rake angle, constant axial rake angle, constant axial clearance angle, and a constant radial clearance angle. The tool includes at least one slot, and preferably three or more slots, disposed at a negative axial rake angle with respect to the centerline of the tool for receiving and mounting a cutting member. Each slot intersects the front axial face of the tool at a location ahead of a plane including the centerline of the tool. A cutting member is a holder for a formed carbide cutter insert. The insert is mounted in the holder such that the forward face of the insert forms an angle with the forward surface of the insert holder which is at least equal and opposite to the negative axial rake angle of the slot so that the face of the insert has either zero or positive axial rake.