An interfering residual magnetism can remain in steel and cast workpieces after machining. If these parts have to be demagnetised for other purposes, this can usually be easily achieved with the tunnel demagnetisers.
For automatic demagnetising on the production line with continuous plastic transport belt and drive motor. The workpieces are moved through the tunnel with a speed of approx. 0.2 m/s. A low-frequency generator can be used as a ballast unit for parts which are difficult to demagnetise.
Because the permanent electro magnetic workholding system is active when the device is de-energised, these chucks are preferably used where long holding times are required and no holding force is required only for short periods or occasionally. They are also used as safety magnets in transport systems and lifting gear, as the load is reliably held during a power failure. To achieve the rated holding force, the steel surfaces of the contact side must be fully covered by the workpiece.