{"product_id":"ngk-standard-spark-plug-lkr6e-9n-4-pack-12mm-thread-26-5mm-reach-copper-core","title":"NGK Standard Spark Plug LKR6E-9N 4-Pack — 12mm Thread, 26.5mm Reach, Copper Core","description":"\u003cstrong\u003eNGK 90410 LKR6E-9N is a four-pack of standard replacement spark plugs engineered for reliable ignition, corrosion resistance, and efficient heat transfer.\u003c\/strong\u003e\n\n\u003cp\u003eThese NGK standard spark plugs combine proven materials and precise construction to serve a wide range of gasoline engines. Built with a copper core, pure alumina silicate ceramic insulator, trivalent plating, and corrugated ribs, each plug is designed to resist seizing, prevent flashover, and move heat away from the firing tip. The 12mm thread with a gasket seat, 26.5mm reach and a .035\" (0.9mm) gap make them compatible with many late-model vehicles and routine maintenance tasks.\u003c\/p\u003e\n\n\u003ch3\u003eHow do these spark plugs resist corrosion and seizing?\u003c\/h3\u003e\n\u003cp\u003eCorrosion and thread seizing are reduced by a trivalent metal plating that creates a durable protective layer on the plug body. The plating offers superior anti-corrosion performance compared with uncoated plugs, which helps during installation and removal, especially in high-moisture or road-salt environments.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eTrivalent plating for improved anti-corrosion properties\u003c\/li\u003e\n  \u003cli\u003eEasier removal after extended service intervals\u003c\/li\u003e\n  \u003cli\u003eMaintains consistent thread integrity under harsh conditions\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat features improve ignition stability and prevent misfires?\u003c\/h3\u003e\n\u003cp\u003eCorrugated ribs on the insulator suppress flashover along the plug surface, helping keep the ignition energy focused at the electrode gap. A solid terminal and a 5K ohm resistor help reduce electromagnetic interference with vehicle electronics while supporting reliable firing characteristics.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCorrugated ribs to prevent flashover\u003c\/li\u003e\n  \u003cli\u003eSolid terminal construction for steady electrical contact\u003c\/li\u003e\n  \u003cli\u003e5K ohm resistor to limit radio frequency interference\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does the plug manage heat for consistent performance?\u003c\/h3\u003e\n\u003cp\u003eThe combined copper core and a pure alumina silicate ceramic insulator provide efficient heat transfer away from the firing tip, helping the plug operate within its intended temperature range. This design supports stable combustion and helps the electrode maintain proper seating and gap over time.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCopper core enhances heat removal from the electrode\u003c\/li\u003e\n  \u003cli\u003eAlumina silicate ceramic insulator offers high strength and thermal conductivity\u003c\/li\u003e\n  \u003cli\u003eTriple seals reduce the risk of combustion gas leakage\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat size and fitment details should I confirm before buying?\u003c\/h3\u003e\n\u003cp\u003eThese NGK plugs use a 12mm thread diameter with a gasket seat and a reach of 26.5mm (1.04\"), so confirm your engine’s thread size and reach match to avoid interference with the combustion chamber. The hex size is 5\/8\" (16mm), and the factory gap is set to .035\" (0.9mm), which can be rechecked and adjusted to the vehicle maker’s specification during installation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThread size: 12mm; seat type: gasket\u003c\/li\u003e\n  \u003cli\u003eReach: 26.5mm (1.04\"); hex: 5\/8\" (16mm)\u003c\/li\u003e\n  \u003cli\u003eTerminal type: solid; gap: .035\" (0.9mm)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The NGK 90410 LKR6E-9N 4-pack is suited for technicians, DIYers, and fleet maintenance teams replacing standard spark plugs on compatible gasoline engines. Choose these plugs when you need durable anti-seize protection, controlled heat transfer, and EMI suppression in a commonly used thread and reach size. Always cross-check with your vehicle’s service manual or parts catalog to confirm correct fitment before installation.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Are these spark plugs pre-gapped?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, they come set to a .035\" (0.9mm) gap, but you should verify and adjust to your vehicle maker's spec before installing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What is the thread and reach of these NGK plugs?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: They have a 12mm thread diameter with a 26.5mm (1.04\") reach and a gasket seat.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"NGK","offers":[{"title":"Default Title","offer_id":55168372703575,"sku":"B081DQ73X8","price":48.61,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/ngk-90410-front-packaging.jpg?v=1790401992","url":"https:\/\/britishgarage.co.uk\/products\/ngk-standard-spark-plug-lkr6e-9n-4-pack-12mm-thread-26-5mm-reach-copper-core","provider":"British Garage","version":"1.0","type":"link"}