Spark plug having specified spark gap dimensional relationships

Spark plug having tapered ground electrode

Spark plug having titanium diboride electrodes

Spark plug having vanadium oxide islands on central insulator

Spark plug having Y-shaped or V-shaped electrodes

Spark plug in use for an internal combustion engine

Spark plug in use for an internal combustion engine

Spark plug including a ground electrode, a center electrode, and

Spark plug including electrode with protruding portion for holdi

Spark plug including ground elcetrode carrier casing

Spark plug incorporating a folded packing situated on an...

Spark plug insulator for use in internal combustion engine

Spark plug insulator structure

Spark plug internal combustion engine

Spark plug of an internal combustion engine

Spark plug of an internal combustion engine

Spark plug of internal combustion engine having glaze layers...

Spark plug power enhancer

Spark plug requiring low discharge voltage and having high...

Spark plug resistant to accidental discharges