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Hydraulic Clamp Cylinder


Area of application

The hydraulic automatic clamp cylinder type HSZ is designed for machines exerting a force of up to about 700 tons. It is particularly suitable for bottom die clamping (with and without clamping edge). The dies to be clamped must have T-slots.

The clamp cylinder is fitted in recesses in the press bed (or ram).

The clamp cylinder places little demands on the periphery of the machine. Its control can easily be combined in the existing machine control system.

Mode of operation

A double-acting hydraulic cylinder, hydraulically controlled, transmits the necessary clamping force to the die.

Release is effected by reversing the hydraulic valve and driving out the tie rod.

The clamping force is applied by:

Distinguishing features

The hydraulically operated clamp cylinder directly produces the necessary clamping force. In so doing, the hydraulic pressure must be maintained throughout the clamping process (optional equipment with releasing non-return valves and pressure switches recommended).

Due to the installation of the cylinder in recesses provided for it in the press bed, the surface of the clamp cylinder ends just below the bed surface; only the tie rod projects from the surface.

Electrical control of the following functions (switches):

Technical data

Switch: an inductive proximity switch;p-n-p normally open contact
Supply voltage: 10-30 V DC
Cable length: ca. 3 m



  • Completely automatic and also purely hydraulic operation
  • Large clamping thickness tolerance
  • Central control
  • Highest standard of safety due to electrical control
  • Low installation cost
  • Low maintenance cost
  • Highest clamping force, despite compact dimensions of the clamp cylinders


The clamp cylinder had a gunmetal-finish housing and a gunmetal-finish tie rod.

It is secured by four bolts, of strength class 10.9 according to DIN 912 (not included). The thread dimension depends on the type (see technical drawing).

Dimensional diagrams

Technical specs