A milling cutter with at least one peripheral cutting edge 4 disposed on its periphery, the peripheral cutting edge 4 being configured as a profile of spaced-apart teeth 7 that forms a so-called cord; wherein each of the teeth 7looking from the flute in a direction opposite to the cutting direction onto the cutting edge portionforms a cutting edge portion SK composed of several different radii, i.e. of at least one larger radius R1 forming the predominant part of the cutting edge portion of the respective tooth 7 and a smaller radius R2, which is preferably immediately adjacent thereto on both sides.

Herein is provided a method of milling a brittle workpiece (46) using a milling tool (10), the workpiece (46) comprising a material, the material having a Ductile-Brittle Transition Undeformed Chip Thickness, DBh.sub.rn, the milling tool (10) comprising a tool shank (12) having an axis of rotation (14), and further comprising a tool head (16) comprising superhard material at one end thereof, the tool head (16) having a diameter (42), and operating the milling tool (10) such that an Undeformed Chip Thickness, h.sub.m, of the workpiece (46) is less than said Ductile-Brittle Transition Undeformed Chip Thickness, DBh.sub.m of the material.

End mill cutter having a plurality of cutting edges distributed over the circumference of the mill cutter, having a flank which is adjacent to the respective cutting edge in the circumferential direction and a supporting surface which adjoins the flank on that side which faces away from the cutting edge in the circumferential direction.

One or more example embodiments of the present invention relates to a fin for collimating therapeutic radiation. The fin comprises a collimation area made of a first material and a holding area made of a second material. Herein, the collimation area and the holding area are pressed together. Herein, the first material is formed to collimate therapeutic radiation. Herein, the holding area can be coupled to an adjustment device for adjusting the fin.