| Part Name | Description |
|---|---|
| Terminal | Connects to the ignition coil and receives high voltage |
| Insulator | Ceramic body that prevents electrical leakage and withstands extreme heat |
| Center Electrode | Carries current to generate the spark |
| Ground Electrode | Forms a gap with the center electrode to produce the spark |
| Spark Gap | The space where the spark occurs to ignite the air-fuel mixture |
| Metal Shell | Steel outer body that supports installation and transfers heat |
| Thread | Enables the spark plug to be screwed into the cylinder head |
| Gasket / Seal | Ensures airtight sealing and prevents combustion gas leakage |
| Resistor | Minimizes electrical interference (EMI) with engine electronics |
| Core Nose | Maintains proper heat range and prevents carbon fouling |