Expander AN -4 Female to -6 Male

The Expander AN -4 Female to -6 Male adapter is a precision hydraulic and pneumatic fitting designed for high-performance fluid systems where size reduction or step-down connections are required. This straight adapter bridges AN -4 (female swivel) ports to AN -6 (male) connections, making it essential for plumbing applications in racing engines, custom cooling systems, fuel delivery, and brake line installations. Whether you're building a competition vehicle or upgrading an existing system, this fitting provides the reliable transition needed to connect different AN line sizes without leaks or flow restriction.

Manufactured by ALLSTAR PERFORMANCE, this adapter is constructed from aluminum and finished with black anodized coating for corrosion resistance and durability in harsh engine bay environments. The female swivel design on the -4 end allows 360-degree rotation for easier installation in tight spaces, while the male thread on the -6 end ensures a secure, leak-free connection when properly seated. Black anodize finish not only protects against oxidation but also provides a professional appearance that integrates seamlessly into custom builds. The straight design minimizes turbulence and pressure drop, critical for maintaining system efficiency in high-flow applications.

This fitting is ideal for fabricators, engine builders, and motorsports enthusiasts working with AN-standard fluid systems where space constraints or plumbing logic require stepping down from -4 to -6 lines. Installation is straightforward—thread the male end into the -6 port and connect the swivel female end to the -4 source, using appropriate thread sealant for positive seal. The compact 4.05-inch length and lightweight 0.04 lbs design make it suitable for under-hood applications where every fraction of an inch matters. Compatible with all standard AN -4 female and AN -6 male fittings, this adapter delivers the precision fit and reliability that competitive builders and professional technicians demand.