4AN to 4 AN Flare Union AN/AN

The 4AN to 4 AN Flare Union AN/AN adapter is a critical hydraulic fitting for high-performance fuel, oil, and coolant systems in racing, marine, and specialty automotive applications. This straight-through connector links two 4 AN male ports directly, eliminating the need for separate hose segments and reducing potential leak points in pressurized line assemblies. Built by REDHORSE PERFORMANCE—a brand trusted by engine builders and professional technicians—this adapter ensures compatibility across modular fuel injection, supercharger, and turbo cooling circuits where AN-standard fittings are standard.

Constructed from lightweight aluminum and finished in blue anodized coating, the 4AN to 4 AN Flare Union delivers corrosion resistance and a professional appearance on engine bays and show vehicles. The flare union design uses a 37-degree JIC flare seat, the industry standard for AN fittings, which creates a metal-to-metal seal that withstands sustained high pressure without relying on rubber gaskets or thread-locking compounds. Weighing just 0.05 lbs and measuring 2.75 inches in length, this compact fitting integrates seamlessly into tight engine compartments without adding bulk or complexity to plumbing layouts.

This adapter suits builders upgrading fuel systems on LS, small-block, and modern turbocharged engines, as well as mechanics servicing aftermarket cooling circuits on high-horsepower platforms. Installation requires a simple wrench connection—no special tools needed—making it ideal for both professional shops and dedicated enthusiasts. Use this fitting whenever two 4 AN male flare connections must be joined in a straight line without directional offset; verify system pressure rating (typically 3,000+ PSI) matches your application requirements before installation.