FIELD: worm gear-cutting tools. SUBSTANCE: changeable cutting plate is made of hard alloy or superhard materials. Plate sides have modified sections which change geometrical profile of initial figure of plate up to profile of worm instrument tooth selected in section adequate to plate parameters. Angles of initial figure geometrical profile for alternating plate vertices are selected by given formula. Every other vertex of plate is provided with flats, and sides of initial figure geometrical profile are reduced for length intercepted by flats. EFFECT: improved stability. 27 cl, 7 dwg, 3 tbl
