MB-S magnetic clamping blocks have a magnetically active clamping surface which is regulated in the adhesive force. The operating shaft on the opposite side of the clamping surface activates the magnet system on the side Mag-level window can be seen whether a full or partial magnetization is set. For holding of gauges and manual machine tools such as Drills, Laser units, Surface treatment machines that need to be brought into position, the MB-S are pushed with part-magnetized clamping surface in the desired position, even on vertical clamping surfaces or overhead. MB-S clamping blocks are shipped with standard drill and drill plan for the introduction of individual fixing holes.