#4 Male to 1/8in NPT Aluminum Gauge Fitting

The #4 Male to 1/8in NPT Aluminum Gauge Fitting from XRP-XTREME RACING PROD. is an essential adapter for any performance or stock engine monitoring setup. Whether you're running a custom turbo platform, installing aftermarket gauges, or upgrading a factory fuel pressure or oil pressure system, this fitting bridges the gap between your gauge sender and the engine block or fuel rail. Built for durability in high-vibration environments, it serves mechanics and enthusiasts who demand reliable pressure signal transmission without leaks or thread stripping.

Manufactured from aluminum, this gauge fitting features a #4 SAE male port (JIC straight thread) on one end and a 1/8-inch NPT (National Pipe Thread) port on the other, allowing seamless integration between metric and imperial gauge systems. The aluminum construction keeps weight minimal—just 0.04 lbs—while maintaining rigidity needed for pressurized fuel and oil lines. NPT threads are tapered, creating a mechanical seal without requiring additional sealant tape, though many professionals still apply PTFE tape for redundancy in critical applications. The compact footprint (2.7 x 0.95 x 3.6 in) makes it easy to install in tight engine bay layouts common on modern turbocharged or supercharged platforms.

This adapter is ideal for builders upgrading to digital or analog gauge clusters, fuel system diagnostics, or installing auxiliary pressure monitoring on race applications. Common uses include turbo fuel pressure measurement, oil pressure gauge installation on LS swaps, or coolant temperature sensor adaptation. Install using an appropriate wrench or socket to avoid rounding the fitting hex, and ensure proper thread engagement to prevent weeping at idle. Compatibility spans most applications where SAE #4 and 1/8in NPT ports intersect—verify your gauge sender and manifold thread sizes before ordering to ensure proper fit.