NGK standard plugs are constructed for longer life and optimum performance. Trivalent metal plating provides superior anti-corrosion and anti-seizing properties Corrugated ribs prevent flashover Pure alumina silicate ceramic insulator, provides superior strength and better heat transfer Copper core aids in heat removal Triple seals prevent leakage   Product Specifications Thread Diameter 10mm Thread Pitch 1.0mm Seat Type Gasket Reach 26.5mm (1.04″) Hex Size 9/16″ (14mm) Terminal Type Solid Gap     .035″ (0.9mm) Center Electrode Material Nickel Type Standard Size 2.5mm Projection Projected Ground Electrode Material Nickel Type Standard Quantity 1 Specifications Resistor Yes Resistor Value 5k Ohm Heat Range 8 Features Extended center electrode Torque Specs Cast Iron: 7.2-10.8 lb. ft. Aluminum: 7.2-8.7 lb. ft.