A method for manufacturing magnet armatures which are used mainly in brake-pressure modulators of electronically controlled brake systems and which are provided on their entire surface with a plastic coating, for reasons of dimensional stability and sliding properties. Magnet armatures of this type are constructed as cylindrical members and are usually provided in the region of one of the two end faces with an elastomeric sealing element, which according to the prior art is bonded to the magnet armature by vulcanization, an adhesive elastomer-to-metal bond being formed between the magnet armature and the elastomeric sealing element during vulcanization. Since bonds of this type are not possible for a completely coated magnet armature, the elastomer for the elastomeric sealing element is, according to the invention, vulcanized onto the armature without using an adhesion promoter. The resulting absence of nonpositive bonding between the elastomeric sealing element and the magnet armature is replaced by the structural feature of an interlocking relationship between the magnet armature and the elastomer. The interlocking relationship is achieved by an undercut in the magnet armature.