Spark plug for an internal combustion engine has an insulator, a central electrode, a tubular metal sleeve, an earth electrode, a resistor and connection electrodes

摘要

A tubular metal sleeve (4) has a hexagonal head section (42) and a section (41) with an external thread formed on the associated outer periphery. The section with the external thread has a nominal size not larger than M14 as specified in Japanese Industrial Standards. The metal sleeve is produced from a conductive metal material, e.g. low-carbon/flexible steel.