The support plunger is retracted in off-position. When pressurised, the support plunger moves against the inserted workpiece by means of spring force. With increasing oil pressure, the support plunger locks hydraulically. After the system has been unclamped, the support plunger returns to the off-position. The support plunger is provided with female thread to enable the use of threaded pieces for height adjustment. Oil supply can alternatively be effected from the side or from below. The internal part of the work support is protected against dust and swarf by a sintered metal air filter.
Hydraulic work supports are used to provide a self-adjusting rest for the workpiece during the machining operations. They compensate the workpiece surface irregularities, also deflection and vibration under machining loads.