FIELD: machine tool manufacture, namely, machine tools for milling non-uniform pitch threads; machine tool includes blank unit, tool unit, tuning device, thread milling circuit and circuit for pitch increment. SUBSTANCE: machine tool includes hydraulic links and cam for pitch increment, hydraulic step drive units mounted in thread milling circuit and in pitch increment circuit. Each hydraulic drive unit includes hydraulic step motor kinematically joined with tool unit and with pitch increment cam, and also tuning unit in the form of hydraulic pulse generator providing desirable gear ratio in said circuits due to necessary relation of hydraulic pulse frequency values. Said relation depends upon number of working slits of rotary spool of slide valves of hydraulic pulse generators. Hydraulic pulse generator is joined with step hydraulic motor trough pipeline system. EFFECT: enhanced accuracy at milling threaded surfaces with variable pitch due to lowered length of kinematic circuits because of reduced number of mechanical links and decreased metal consumption. 1 dwg
