4AN to 3AN Reducer Blue Female Male

The 4AN to 3AN Reducer Blue Female Male adapter from REDHORSE PERFORMANCE is an essential fitting for any serious automotive enthusiast or mechanic working with high-performance fuel systems, hydraulic lines, or custom cooling circuits. This adapter bridges two common AN (Army-Navy) line sizes, allowing you to connect 4AN female ports to 3AN male connections—a critical component when downsizing line diameter or integrating components with mismatched port sizes. Whether you're building a custom fuel delivery system, upgrading a nitrous setup, or fabricating a bespoke cooling loop, this reducer eliminates the need for costly custom hose assemblies and provides a clean, leak-free connection point.

Constructed from precision-machined aluminum and finished in vibrant blue anodized coating, the 4AN to 3AN reducer combines lightweight durability with superior corrosion resistance—essential for engine bays and fuel cell compartments exposed to heat cycles and moisture. The anodized finish also provides visual identification in complex plumbing systems, reducing installation errors and simplifying future maintenance. The 950 Series design ensures proper thread engagement and face-seal compatibility with standard AN fittings, eliminating micro-leaks that can plague amateur installations. At just 0.06 lbs, this adapter adds negligible weight while maintaining the structural integrity required for fuel pressures commonly exceeding 60 PSI in modern fuel injection systems.

This reducer is ideal for custom fuel system builders, turbo installers, and anyone transitioning between different AN line standards in performance applications. Installation requires only a wrench or AN wrench—no special tools—and the compact 2.85 x 1.1 x 3.75-inch footprint fits easily into tight engine compartment layouts. Use with quality AN hose assemblies rated for your system pressure and fluid type, and always verify male and female orientations before final assembly to prevent cross-threading. Compatible with any AN-standard fitting ecosystem, this adapter is a workshop staple for professional and amateur builders alike.