A new method for manufacturing a ferromagnetic part for an electromagnetic contactor, the ferromagnetic part having both particularly high impact mechanical durability, good ferromagnetic properties and good corrosion resistance, while integrating a non-magnetic gap. The method includes the following successive steps: a step a) of supplying a soft ferromagnetic metal blank part; and a step b) of electroless nickel plating at least one section of the blank part in order to obtain the ferromagnetic part, the section of which is surface coated with a nickel surface layer, with the obtained ferromagnetic part including the soft ferromagnetic metal, which, for at least one electroless nickel plated section, is disposed under the nickel surface layer.