The self-locking nut, code number K 27417, is specially designed for secure fastening of the spindle (K 27401) in the starting valve system of the ZV40/48 engine. Its self-locking feature prevents loosening due to vibrations or pressure fluctuations, thus maintaining the correct positioning and alignment of the starting valve. Made from high-grade materials with anti-corrosive properties, this nut plays a critical safety role, ensuring the reliability of engine starts over prolonged operational cycles.