#4 Female x #6 Male Swivel Expander Black

The #4 Female x #6 Male Swivel Expander Black from FRAGOLA is a precision hydraulic and fuel line fitting designed for builders and mechanics who demand reliability in high-pressure systems. This adapter bridges two different line sizes, allowing you to connect smaller #4 ports to larger #6 ports without modifying existing hardline runs or investing in costly replacement sections.

The swivel design allows ±45-degree articulation, reducing installation stress on both the male and female connections and protecting against vibration-induced cracking common in rigid adapters. Black anodizing provides corrosion resistance and a professional finish that withstands engine bay heat, road salt, and ethanol-blended fuels. This adapter excels in custom fuel systems, EFI conversions, turbo return lines, and transmission cooler loops where size mismatches are common in mixed-component builds.

Whether you're fabricating a custom fuel delivery system or adapting OEM components to an aftermarket setup, this swivel expander eliminates the need for stepped fittings or restrictive adapters that compromise flow. The #4 female thread accepts smaller hardline fittings, while the #6 male end connects to larger ports, creating a seamless transition without dead legs or turbulent flow interruption.