A jacquard thread-guide bar (2) for warp knitting textile machines, comprising a supporting body (7) provided with a plurality of housing seats (5) configured and arranged so as to engage each removably a mounting body (6) of a single piezoelectric actuator (3) and to carry out an individual removable mounting of the single piezoelectric actuator (3) onto said supporting body (7), the housing seats (5) extending perpendicularly to the main longitudinal extension of the bar (2) and being configured and arranged so as to guide the sliding of the mounting body (6) between a mounting position and a disengaged position.