#4 An Flare To 1/2in Pipe

The #4 AN Flare to 1/2in Pipe fitting from Aeroquip is an essential adapter for high-performance fuel and fluid systems in custom engine builds and modified vehicles. Whether you're upgrading a carburetor feed line, installing a fuel injection system, or routing brake fluid in a race car, this fitting bridges AN (Army-Navy) flare connections to standard NPT pipe threads with precision engineering. Mechanics and enthusiasts rely on these adapters when OEM routing won't accommodate performance fuel systems or when consolidating multiple line types into a unified platform.

Aeroquip's #4 AN flare fitting delivers proven durability through quality brass or aluminum construction designed to handle both low and high-pressure applications without leakage or thread stripping. The AN flare connection side features the characteristic 37-degree flare seat that locks fuel or hydraulic fluid tightly, while the 1/2-inch NPT pipe thread end screws directly into engine block fittings, fuel rails, or manifold ports without requiring additional adapters. This two-in-one approach eliminates cascade fitting chains, reduces connection points, and improves system reliability—critical factors when fuel system failures can catastrophically damage an engine or compromise brake performance.

Custom builders prefer this fitting for LS engine conversions, carbureted fuel system installations, and vintage hot rods where modern EFI systems must interface with legacy manifold ports. The compact 2.2 x 1.15 x 3.8-inch form factor fits tight engine bays and complex plumbing layouts without obstruction. Always verify your specific NPT port size and AN line diameter before ordering; this #4 AN unit pairs with -4 hose or tubing and 1/2-inch NPT threaded ports found on many performance fuel pumps, carburetors, and cylinder head fittings.