4AN Male Flare to M10x1.0 Inverted Adapter

The 4AN Male Flare to M10x1.0 Inverted Adapter by REDHORSE PERFORMANCE is a precision hydraulic fitting engineered for custom fuel, oil, and coolant line configurations in high-performance automotive builds. This adapter bridges two industry-standard connection types, making it essential for mechanics and fabricators who need flexible plumbing solutions without compromising system integrity. Whether you're upgrading a fuel delivery system, relocating a cooler, or custom-routing brake lines, this adapter eliminates the need for multiple components and reduces potential leak points in critical vehicle systems.

Constructed with REDHORSE PERFORMANCE's reputation for durability, this adapter features a 4AN male flare connection on one end and an M10x1.0 inverted metric thread on the other, allowing seamless integration between aftermarket -4 braided hose assemblies and metric component ports. The inverted design prevents cross-threading and ensures a positive seal under pressure, critical for fuel injection systems, turbocharger oil lines, and custom cooling applications. The compact 2.8 x 1.1 x 3.8 inch form factor and lightweight 0.05 lb construction make it ideal for tight engine bay installations where space is at a premium and weight savings matter.

Fabricators routinely specify this adapter for European and import vehicle modifications, where metric fasteners are standard but -4AN hose lines offer superior flow and pressure ratings. It's particularly valuable in turbo installations, fuel system upgrades, and engine swaps where OEM metric ports need to accept performance-grade braided lines. Proper installation requires hand-tightening the inverted thread connection until snug, then applying slight additional torque with appropriate wrenches to achieve a leak-free seal without over-tightening the flare end, which could damage the hose assembly.