Holding disks GN 70 are used as companion parts for retaining magnets, e.g. if a magnet is to be used in connection with non-magnetic materials.
Type B prevents the magnet from sliding since the magnetive forces are generally larger than the achievable lateral forces arising due to the friction partners present.
They can be fixed with countersunk screws (e.g. DIN 7991), but also with any commercial wood or sheet metal countersunk screws.
