#4 Union Fitting Black

The #4 Union Fitting Black from FRAGOLA is a precision hydraulic and fuel system adapter designed for demanding applications where straight-through connections between two male 4 AN ports are required. This adapter serves as an essential component in custom fuel systems, hydraulic lines, and high-performance engine builds where reliable, leak-free connections are non-negotiable. Whether you're building a race engine, restoring a classic vehicle, or designing a custom fluid delivery system, this union fitting provides the dependable connection point your project demands.

Machined from aluminum and finished in black anodize coating, the #4 Union Fitting Black combines strength with corrosion resistance. The 4 AN male-to-male straight configuration eliminates the need for additional adapters, reducing potential leak points and simplifying line routing in tight engine compartments. Black anodized aluminum construction provides durability while resisting oxidation and wear in harsh under-hood environments. The straight design maintains consistent flow characteristics and pressure ratings, ensuring system integrity across high-pressure and high-temperature operating conditions typical of fuel injection systems and hydraulic brake applications.

This fitting is ideal for fabricators, performance shops, and DIY builders working with AN-spec fuel and hydraulic systems. Its compact footprint (3.15 x 3.9 inches) makes it suitable for installations where space is limited, and the lightweight aluminum construction (0.02 lbs) won't add unnecessary bulk to your system. Compatible with all standard 4 AN hose and line assemblies, this union fitting integrates seamlessly into carbureted fuel systems, EFI applications, and custom hydraulic brake lines. Proper installation requires AN-spec wrenches and thread sealant rated for your specific fluid type—always verify compatibility with your fuel or hydraulic medium before assembly.