Abstract: A molding unit (10) for the manufacture of containers from preforms made of thermoplastic, includes compensating elements which are formed of at least one gripper (60) which acts on mold carriers (16) that carry the mold (12) of the unit (10) in order to clamp them against one another when the molding unit (10) is in the closed position and to apply a compensating force that tends to clamp together molding elements (14) of the mold (12) at a parting line (P) and opposes the forces that a pressurized fluid applies to the molding elements (14) when a container is being molded from a preform.