FIELD: processing of materials. SUBSTANCE: invention relates to the processing of materials by cutting and can be used in the design of cutting tools designed for processing flat surfaces by milling. Cylindrical cutter with helical teeth contains on one side helical teeth with a constant circumferential pitch . On the other side, the teeth are made with a variable non-repeating circumferential pitch . The first tooth is located with the angle of inclination of the helix relative to the axis of the cutter equal to , and each subsequent i tooth - with the angle of inclination of the helix equal to . Correlations for determining the indicated angles are given. EFFECT: resonance during the operation of the cutter is reduced, the quality of the machined surface is increased, and the tool life is increased. 1 cl, 5 dwg.