Patent ID: 8866369

Claim:
A spark plug for being threaded into a cylinder head and extending into a combustion chamber for providing a spark to ignite a combustible mixture of fuel and air in the combustion chamber, comprising: a shell formed of metal extending from a shell upper surface to a shell lower surface, said shell including a shell outer surface between said shell upper surface and said shell lower surface including a plurality of threads for threading into a cylinder head, a ground electrode formed of an electrically conductive material attached to said shell lower surface for being disposed in a combustion chamber, and said threads being disposed at a predetermined angle relative to said ground electrode allowing said ground electrode to be disposed in a predetermined position in the combustion chamber when said shell is threaded into the cylinder head, wherein the spark plug is formed by a process comprising the steps of: determining said predetermined location of said threads to be formed in said shell outer surface relative to said ground electrode, providing a thread forming apparatus for forming said threads in said predetermined location relative to said ground electrode when said ground electrode is disposed in a predetermined position relative to said thread forming apparatus, using an orientation tool to dispose said ground electrode in said predetermined position relative to said thread forming apparatus, wherein said orientation tool includes a tool outer surface extending longitudinally along a tool central axis from a first end to a second end and includes a thread orientation feature extending transverse to said tool outer surface, and the step of using said orientation tool including disposing said orientation tool in a predetermined location relative to said thread forming apparatus such that when said ground electrode contacts said thread orientation feature said ground electrode is disposed in said predetermined position relative to said thread forming apparatus, aligning an igniter central axis of said shell with said tool central axis, disposing said ground electrode along said tool outer surface, rotating said shell relative to said orientation tool until said ground electrode contacts said thread orientation feature, and forming said threads in said shell outer surface by said thread forming apparatus while said ground electrode contacts said thread orientation feature.