Abstract: An apparatus for demagnetizing parts after they have been subjected to the action of a magnetic field having coils (1,2) connected to an a-c power supply source and disposed one inside the other at one and the same angle with respect to a trough (3) extending through the inner coil. The coils (1,2) are mounted in such a manner that the angle (.alpha.) therebetween can be adjusted.

Abstract: A method for determining force characteristic of a device for magnetically holding workpieces placed on a top plate (3) of the device, wherein a workpiece (1) cooperating with a source of magnetic field of the device is connected to a force pick-up (2) and is caused to move along the top plate (3), along a test line (4). The source of magnetic field remains permanently energized during the tests, the workpiece (1) is placed in parallel with the top plate (3) with a clearance which depends on sensitivity of the force pick-up (2), and is caused to move along the test line (4) continually while maintaining the amount of the clearance substantially unchanged.

Abstract: A method of manufacturing the adapter of a multipole slab includes assembling simultaneously a stack of alternating plates of magnetic steel and non-magnetic steel, a solder and a thin-wall steel container of which the walls sealingly enclose the stack of the plates and the solder. Then the container with the stacked plates and solder therein is heated to a soldering temperature, and subsequently cooled. Then the walls of the container adjoining the edges of the stacked plates are removed.

Abstract: A device for magnetically holding workpieces to be machined on machine-tools has a magnetic field source (3, 4) and, disposed thereon, a plate (5) whose side adapted to support workpieces (I) has recesses (6) intended to define magnetic poles. The plate (5), in its side facing the magnetic field source (3, 4), has auxiliary grooves (7) shifted with respect to the recesses (6) in such a manner that the distance (b) from the bottom of the recess (6) surface of to the of the plate (5) facing the magnetic field source (3, 4), the distance (a) between the recess (6) and auxiliary groove (7), and the overlap (c) between the recess (6) and auxiliary groove (7) are substantially equal to one another.