Patent ID: 8407891

Claim:
A method comprising: forming a spark plug housing in an engine structure using a tool having a longitudinally extending body including a seat forming portion and a thread forming portion, the forming including advancing the tool a first distance in a first axial direction into the engine structure to create a spark plug seat using the seat forming portion, the thread forming portion extending from the seat forming portion and into a spark plug bore extending through the spark plug seat; displacing the tool a second distance in a second axial direction generally opposite the first axial direction after the forming to provide a predetermined axial orientation between the thread forming portion of the tool and the spark plug seat based on the first and second distances; and engaging the spark plug bore at a first predetermined rotational and axial position and displacing the tool in an orbital motion and in the second axial direction beyond the second distance at a predetermined rate to form a threading on the spark plug bore providing a starting point of the threading at a second predetermined rotational position proximate the spark plug seat.