FIELD: metal cutting, namely broaching thin-wall grooves. SUBSTANCE: method comprises steps of working groove at three stages by means of three groups of broaching sections. Broaching unit is in the form of sections mounted on tool plate. In order to enhance quality of product due to using different schedules of cutting, first group of broaching sections removes allowance with large feed for tooth by depth more than half-depth of groove; second group of broaching sections removes allowance with small feed for tooth and third group of sections forms groove angles and trims its lateral surfaces. Broaching unit includes three groups of sections. First group of sections operates in to mode of cutting with large feed for tooth, it has inclination angle of main cutting edge equal to 0 degrees and recesses for free removal of chip. Second group of sections operates in mode with small feed for tooth, with shifting of additional cutting edges of section relative to worked walls of groove and it has inclination angle of main cutting edges equal to 15 degrees. Third group of section operates in profiling mode with two main cutting edges having inclination angle equal to 15 degrees for each tooth. EFFECT: enhanced efficiency of method, improved design of broaching unit. 3 cl, 8 dwg
