Spark plugs are important components of the ignition system in gasoline engines. They can introduce high-voltage electricity into the combustion chamber and cause it to jump over the electrode gap to generate sparks, thereby igniting the combustible mixture in the cylinder. It mainly consists of wiring nuts, insulators, wiring screws, central electrodes, side electrodes, and the shell, with the side electrodes welded to the shell.

Spark plugs are key components of engines, consisting of a steel shell, central electrode, insulator, and side electrode. The lower part of the steel shell has a fine thread, which is used to fit with the spark plug hole in the cylinder head. The upper part has an outer hexagonal nut, which is used to fit the spark plug sleeve to tighten or unscrew the spark plug. The central electrode is a metal rod, with the lower end in contact with the upper end of the central electrode through a conductor glass body. The upper end of the metal rod is equipped with a wiring nut. There is a high alumina ceramic insulator between the steel shell and the central electrode, which insulates the central electrode when energized. The bottom part of the steel shell is equipped with curved side electrodes. There is a copper washer in the middle of the outer part of the steel shell.