# SILMAR9A9S Iridium Spark Plug

NGK iridium spark plugs currently represent the highest-quality technological solution. They feature an iridium-alloy on the middle electrode welded on in a special process using a laser. One of the world's hardest metals, the precious metal iridium starts melting at a temperature of 2450°C and is therefore very resistant to spark erosion. By using it, the service life is doubled on average in comparison to standard nickel spark plugs.

**Shell**

-   Thread Size: 10mm
-   Thread Pitch: 1.0mm
-   Seat Type: Gasket
-   Resistor Value: 5K Ohm
-   Reach: 26.5mm (1.04")
-   Hex Size: 14mm (9/16")
-   Terminal Type: Solid
-   Overall Height: ISO
-   Gap: 0.9mm (0.035")

**Centre Electrode**

-   Material: Iridium
-   Type: Fine Wire
-   Size: 0.6mm
-   Projection: Projected

**Ground Electrode**

-   Material: Platinum
-   Type: Standard
-   Shape: Taper Cut
-   Quantity: 1

**Specifications**

-   Heat Range: 9
-   Resistor: Yes

## Details

- **Price:** 40.5 AUD
- **Vendor:** NGK
- **Tags:** NGK Spark Plugs | Marine Automotive & Small Engine Ignition

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 40.50 AUD | In stock |

## Images

- SILMAR9A9S Iridium Spark Plug

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/silmar9a9s-iridium-spark-plug)
> Updated: 2026-06-23