#4 Male Steel Inverted Flare Adapter

The #4 Male Steel Inverted Flare Adapter from XRP-XTREME RACING PROD. is a precision hydraulic fitting designed for high-performance fuel systems, brake lines, and power steering applications in modified vehicles. This adapter bridges 4 AN male connections to 10 mm x 1.00 inverted flare male ports, making it essential for custom engine builds, fuel injection conversions, and motorsport suspension upgrades where OEM-style fittings don't match modern aftermarket component threads. Whether you're restoring a classic hot rod with contemporary fuel delivery or upgrading a track car's hydraulic systems, this straight adapter eliminates costly line modifications and ensures leak-free operation under pressure.

Constructed from steel and finished with nickel plating, this adapter resists corrosion and thermal cycling while maintaining structural integrity under high-pressure service. The inverted flare design—a proven standard in motorsport and industrial hydraulics—creates a tapered seat that distributes clamping forces evenly, reducing stress concentration and fatigue failure at the fitting interface. Inverted flare connections are superior to straight-thread designs for demanding applications because they self-center during installation and tolerate minor surface imperfections without sacrificing sealing performance. The nickel plating adds durability against fuel, brake fluid, and power steering fluid, while the compact form factor (weighing just 0.09 lbs) minimizes installation complexity in tight engine bays or chassis tunnels.

This fitting is ideal for engine builders, fabricators, and enthusiasts performing fuel system upgrades, brake line rerouting, or custom hydraulic plumbing. It pairs seamlessly with XRP-XTREME RACING PROD. hoses and fittings, a brand trusted by drag racers, road course competitors, and street performance shops. Proper installation requires using the correct wrench sizes and torque specifications for AN fittings—typically hand-tight plus ¼ turn—to avoid over-tightening and damaging the delicate flare. Stock this adapter when ordering complete fuel or brake line kits, or keep extras on hand for troubleshooting fitment issues during engine swaps or system modifications.