wire when the latter has a diameter greater than that of the mandrel 10 u2032 a 10 u2032 b the thickness of the different layers applied takes account of their expansion with a view to the result that is desired after cic treatment the cover system 12 u2032 as represented in fig7 is adapted to the outer geometry of the preform according to another production variant the method of the invention makes it possible to manufacture parts in dumbbell form that is to say with transverse radial ribs to obtain them it is sufficient to adapt the geometry of the second layer so as to form these ribs the thickness of this second layer is increased for this purpose in the desired position thus fig8 shows a detail of the preform produced in this way the second layer 8 u2033 of metal wire is formed by winding metal wire so as to exhibit a part forming a transverse rib 8 u2033 a this rib after the cic treatment forming a transverse radial rib on the part the function of this rib may be a terminal fixing flange or a pinion after machining radial teeth in order to further reinforce the mechanical strength of this rib ceramic fibers 8 u2033 b of a length adapted to the width of the rib after cic can be included if the reinforcing fibers are oriented transversely to the axis of the part then they can be put in place by winding in the same way as.