Abstract: Fuel injection nozzle for internal combustion engines comprising an inwardly opening valve needle (14) and a nozzle bore hole (20) into which a throttle pivot (18) of the valve needle (14) dips during an initial lift. The throttle pivot (18) is provided with at least two flattened portions (30, 32 and 30, 32, 40, respectively) for forming preferred pass-through cross sections in the nozzle bore hole (20), wherein at least two flattened portions (30, 32 and 32, 40, respectively) end in different cross-sectional planes of the throttle pivot (18). Accordingly, a stepwise enlargement of the total cross section in the nozzle bore hole (20) can be achieved during the initial lift of the valve needle (14) with manufacturing methods which can be controlled in a favorable manner.

Abstract: Fuel injection nozzle for internal combustion engines includes a nozzle element having a front cusp formed with a conical valve seat face. At least one injection hole is provided in the front cusp. The outer wall area of the front cusp which is disposed opposite to the valve seat face has a lower hardness than that of the inner wall area forming the valve seat face. When the injection hole extends from a pocket hole, preferably the outer wall area of the front cusp encompassing the picket hole has a lower hardness than that of the opposite disposed inner wall area. The intermediary center wall area preferably has a still lower hardness than the outer wall area. Thus, it is achieved that the front cusp of the nozzle element has a higher rigidity than in a known embodiment, without the valve seat face losing any hardness or that the protection of the outer wall area of the front cusp being unduly severly reduced against abrasive wear.