Easily removable spark plug

摘要

A spark plug comprised of a spark plug main body and a cylindrical pressing member used for mounting the spark plug main body on an internal-combustion engine. The spark plug main body includes a cylindrical metal shell. A removing-tool engagement portion is formed on an outer circumferential face of the metal shell at a front end side of a caulking portion. The removing-tool engagement portion is used for engaging with a tool, when removing the spark plug main body from a plug hole of an internal-combustion engine.