3AN to 4AN Reducer Black Male Male

The 3AN to 4AN Reducer Black Male Male from REDHORSE PERFORMANCE is a precision hydraulic and fuel line adapter engineered for high-performance automotive, racing, and industrial fluid systems. This straight-through reducer fitting transitions from a 4 AN (5/16-inch) male port to a 3 AN (1/4-inch) male port, making it essential for builders who need to step down line sizes while maintaining system integrity. The adapter is commonly used in fuel delivery systems, cooling circuits, and pressurized fluid applications where size compatibility and leak-free connections are non-negotiable.

Constructed from aluminum and finished in black anodized coating, this 919 Series fitting delivers corrosion resistance and durability in demanding environments. The anodized surface protects against oxidation while the aluminum core maintains excellent strength-to-weight ratio—critical for racing platforms where every fraction counts. The straight design ensures minimal turbulence and pressure drop across the reducer, preserving flow efficiency and system performance. Both ports feature male threads, allowing direct connection to female AN ports on radiators, fuel rails, filters, and manifolds without additional adapters.

Engine builders, custom fabricators, and performance technicians rely on REDHORSE AN fittings to create clean, reliable plumbing in fuel injection systems, turbocharger circuits, and modified cooling loops. The compact 2.75 × 1.1 × 3.75-inch footprint fits tight engine bays without sacrificing accessibility. This reducer is sold individually, allowing you to source exactly the adapters your system requires. Compatible with any standard AN female port and recommended for use with REDHORSE hose assemblies and complementary 919 Series fittings to ensure system-wide compatibility and maximum reliability.