Patent ID: 8568181

Claim:
A method of forming a spark plug including an insulator having a first section at a first end of the insulator, a second section, and a third section at a second end of the insulator opposite the first end of the insulator, wherein the second section is disposed between the first and third sections, the insulator further including a channel formed between the second and third sections and a first shoulder formed between the first and second sections, a two-piece outer shell disposed about the insulator, and a center electrode disposed within a passage in the insulator, the method comprising the steps of: inserting the insulator into the two-piece outer shell such that: a first end of a first piece of the outer shell is adjacent the first end of the insulator and a second end of the first piece is disposed adjacent the first shoulder of the insulator; a second piece of the outer shell is configured to include a first end, an opposite second end, a threaded portion located between the first end and the second end, and a jamb nut portion located between the threaded portion and the second end; and the first end of the second piece of the outer shell is adjacent the second end of the first piece of the outer shell, and the second end of the second piece of the outer shell is disposed adjacent a second shoulder of the insulator and the channel of the insulator; overlapping the first end of the second piece of the outer shell to the second end of the first piece of the outer shell at the first shoulder; and crimping the second end of the second piece of the outer shell around the second shoulder to extend into the channel of the insulator.