spark plug

Abstract

A spark plug (100) comprising: a tubular metal casing (50) with a fastening screw section (52) having an external thread, wherein the fastening screw section (52) has: a section with maximum pitch diameter (D1) at which the external thread has a maximum pitch diameter, wherein the section with maximum pitch diameter (D1) is located at a rear end face of a center of the fastening screw section (C, 52) in a direction along an axial line of the metal casing (CA, 50), and a section with a local maximum of the pitch diameter (D2) at which the external thread has a locally maximum pitch diameter, wherein the section of the local maximum of the pitch diameter (D2) is located at a front end face of the section of the maximum pitch diameter (D1) in the direction along the axial line (CA).

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