Crimping machine for chemical-fiber filaments with crimping chamber having an oscillating upper plate loaded with a closure force for imparting a pressure on the tow which passes through the crimping chamber, wherein the plates of the crimping chamber are mounted on respective supports through two or more linear guides provided with a roller or ball recirculation system. The longitudinal operating position is determined by two pairs of hydraulic cylinders, having an axis parallel to the linear guides, which maintain the plates, or a portion thereof, pushed against respective fixed abutments without the use of further mechanical or oleodynamic blocking elements. Load cells are arranged between the abutments and the plates, for detecting the variations of the tightening force during machine operation, the variations, representative of the variable longitudinal force imparted by the filaments of the tow being processed on the plates, are used for monitoring the quality of the crimp obtained.