Direct clamping with a membrane from Schunk

Schunk Intec Ltdvisit website


Schunk is enlarging its programme for high-performance direct clamping with the SPM Plus 138 fixture membrane. Manufactured from aluminium, the SPM Plus provides the clamping of a multitude of geometries from all sides with its innovative pull-down effect.

Firstly, a 0.5mm-high tuning ring is inserted between the quick-change pallet module and the fixture membrane, and then the exact workpiece geometry is milled according to the blank on the fixture’s clamping surface. Once prepared, the workpieces can be inserted within seconds and the complete circumference is clamped by locking the VERO-S module, which in turn deforms the fixture membrane to provide the clamping.

Since the whole process is carried out within the elastic range of aluminium, the clamping operation can be repeated several thousand times. In contrast to conventional clamping blocks, the clamping force of this clamping method is carried out at the circumference of the whole workpiece contour and not just along an axis. The resulting force-fit clamping ensures an even, gentle and very secure clamping set-up. The membrane is actuated via an SPC quick-change clamping pin that connects with the pneumatically actuated quick-change pallet module.

Due to the clamping depth of only a few millimetres, the workpiece is fully accessible from five sides. The fixture membrane can be located on the quick-change pallet module with a repeat accuracy of less than 0.01mm. The use of an additional clamping unit is unnecessary. If required, it can be machined several times, and different workpiece geometry can be used. The clamping unit is suitable for light machining of various materials and workpiece contours for the second set-up. The maximum workpiece diameter amounts to 120mm.

To learn more about the SPM Plus 138 fixture membrane from Schunk, please visit

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