A method is disclosed for forming a fuel feed passage in the feed arm of a fuel injector. Said sprung blade projects beyond the wiper strip in the area of the connecting element and is enclosed by guide rails that are interlinked by at least one spring clip and secured in the longitudinal direction of the wiper blade by at least one locking element which laterally engages with a recess of the sprung blade. This can be obtained by molybdenum doped with between 0.