Champion Industrial Plug Number W10 Spark Plug - 510 Part #: 510 Line: CHP Champion Industrial Plug Number W10 Spark Plug 1 Year Limited Warranty Seat: Gasket Thread Size: 7/8-18 Inch Heat Range: 10 Hex Size (mm): 23mm Hex Size (in): 15/16 Inch Preset Gap (in): 0.025 Inch Preset Gap (mm): 0.64mm Thread Reach (in): 0.625 Inch Center Electrode Tip Material: Nickel Ground Electrode Tip Material: Nickel Service Number: W10 Metallurgy: Copper Show More Show Less