cores 1 a polymerization and a formation of a polymer film then ensue the thickness of the polymer film can thereby be designationally set by the supply of para xylylene monomers given toroidal tape wound cores a polymer film layer thickness between 5 and 60 u03bcm has proven especially suited since the poly para xylylene film arising in this way exhibits a melting point of gt 275 u00b0 c a temperature stable winding protection arises so that the toroidal tape wound core coated in this way as component part of an inductive component withstands demands corresponding to a soldering process made of surface mounted components smd without melting or respectively without damage to the component in particular toroidal tape wound cores having an outside diameter between 2 and 15 mm can thus be provided with a winding protection that is supplied in the cost beneficial drum process further toroidal tape wound cores coated in this way are suitable for the manufacture of transformers and repeaters wherein freedom from partial discharge is demanded due to the presence of high voltages the polymers disclosed in the invention can be commercially obtained under the registered mark galxyl u00ae from technipol italy as well as under the trade names parylene from novatran of great britain and alpha metals l u00f6tsysteme gmbh germany the process as shown in fig3 b has a first step of vaporizing the dimer the vaporized dimer is then decomposed or pyrolized to form a monomer this is introduced into the vacuum chamber for deposition onto the cores disposed therein subsequently any remaining gas goes through a cold trap which.