NGK Iridium IX Spark Plugs NGK Iridium IX spark plugs feature an ultra-fine center electrode that’s designed just thick enough to ensure the maximum durability and life of the spark plugs—and just thin enough to create an accurate and consistent spark. They represent the ultimate evolution of spark plug technology and performance. Iridium is the hardest metal used in spark plugs today—six times harder than platinum. This allowed NGK engineers to reduce the voltage requirement for a spark. Iridium IX plugs are available in more than a hundred configurations for universal and vehicle-specific applications. Spark Plug Thread Size: 14mm Spark Plug Reach (in.): 0.984 in. Spark Plug Reach (mm): 25.00mm Manufacturer Heat Range: 7 Shorty Spark Plug: No Resistor: Yes Electrode Tip Material: Iridium Electrode Core Material: Copper Center Electrode Type: Projected Spark Plug Seat Style: Tapered Wrench Diameter: 5/8 in. Ground Strap Quantity: One
