Abstract: The invention relates to a fuel injector having an electromagnet 2 which contains a magnet core 6 and a coil 7 and which further has an armature 9 that is guided on an armature pin 8. The armature pin 8 is guided in a guide sleeve 11 which projects into the electromagnet 2. The fuel injector further has an injector body 4 with at least one injection opening which is introduced into the injector body 4 and which is controlled by an injector needle 5. The aim of the invention is to provide a fuel injector which is functionally improved with respect to the switching times of the fuel injector and the forces that can be generated in the fuel injector while simultaneously simplifying a guide sleeve for an armature pin. This is achieved in that the guide sleeve 11 is integrated into the magnet core 6 and is connected to the magnet core 6 in a formfitting or bonded manner.

Abstract: A device for testing the scratch resistance of a surface of a test specimen by means of a gas stream charged with solid particles, comprising: a tube, having an entry and an exit, for directing the gas stream on to a specimen holder with the surface to be tested, a means for providing the gas stream, and a metering device positioned along the tube for metering the solid particles into the gas stream, wherein a tube part is angled at an angle in the region of the tube exit and the angled tube part has, at the angle, an opening at which the specimen holder is positioned such that the gas stream is directed on to the specimen holder.