Key Features & Benefits – NGK Iridium IX iridium spark plug
The NGK Iridium IX iridium spark plug is a resistor-type, iridium-center-electrode plug designed to support consistent ignition. By specification it uses an M14x1.25 thread with a 12.7 mm reach, making it suitable where those dimensions and design are required.
It features a flat gasket seat, a single ground electrode, and a 20.8 mm hex for installation. The built-in suppressor resistance is 5 kOhm, which can suit ignition systems that specify a resistor plug.
When is this useful?
It’s useful when you want repeatable ignition and straightforward servicing while keeping the exact thread, reach and heat range that your engine specification calls for, including a resistor-type plug design.
Technical specs
- Product type: spark plug
- Series: NGK Iridium IX
- Thread size: M14 x 1.25
- Reach: 12.7 mm
- Hex size: 20.8 mm
- Heat range: 6
- Resistance: yes, 5 kOhm
- Seat: flat gasket seat
- Electrodes: iridium center electrode, 1 ground electrode
- Spark position: 3.5 mm
- Terminal: removable SAE terminal
- Weight: 0.06 kg
- Recommended quantity: 4 pcs
Selection & installation tips
- Match your OEM specification for thread size (M14x1.25), reach (12.7 mm) and heat range (6) to ensure proper fit and operating temperature.
- Confirm your cylinder head uses a flat gasket seat and that the plug’s seat type matches.
- Check the plug lead/cap connection for the removable SAE terminal so the electrical connection is secure.
- Allow for tool access around the 20.8 mm hex, especially on tight engine bays or motorsport installations.
- If your engine uses multiple plugs, compare the recommended quantity (4 pcs) to your cylinder count and keep the set consistent by specification.
Before installation, verify thread, reach, seat type, terminal style and resistor requirement, then compare those items directly to the technical specs above and your engine’s OEM plug specification.
