An injection molding method for manufacturing a functional part having a recess, e.g., a borehole, includes a) injecting a first thermoplastic component into an injection mold, in the cavity of which a first mold core is situated, b) replacing the first mold core with a second mold core, the second mold core being smaller than the first mold core, and the second mold core being situated in the cavity formed in the first thermoplastic component by the first mold core in such a way that the second mold core is situated at a distance from the first thermoplastic component by an intervening space, c) injecting a second thermoplastic component into the space between the second mold core and the first thermoplastic component, and d) removing the second mold core.