6AN Female Swivel To 1/4NPT Male Adapter STR

The 6AN Female Swivel to 1/4NPT Male Adapter STR from REDHORSE PERFORMANCE is an essential hydraulic and pneumatic fitting for custom fuel, coolant, and vacuum line installations in modified engines and aftermarket fuel systems. This straight adapter serves as a critical bridge between AN (Army-Navy) hose fittings and NPT (National Pipe Thread) ports, making it indispensable for builders integrating modern fuel injection systems, nitrous oxide kits, turbo plumbing, and custom cooling loops into vehicles where OEM ports use different threading standards.

The 6AN female swivel connection accepts standard -6 AN hose and fittings, while the 1/4 NPT male end threads directly into NPT-ported components such as fuel rails, regulators, gauges, and aftermarket manifolds. The swivel design on the female end permits 360-degree rotation under load, eliminating hose kinking and reducing stress on crimp fittings during engine movement and vibration—a critical feature in high-output applications where thermal expansion and vacuum cycles demand flexible, leak-free connections. REDHORSE PERFORMANCE's aluminum construction and precision-machined threading ensure tight seals when paired with appropriate thread sealant (PTFE tape or liquid sealant), while the straight (STR) configuration minimizes installation footprint in tight engine bays.

Mechanics and engine builders rely on this adapter when retrofitting forced-induction systems, custom fuel cell kits, or standalone EFI platforms into legacy vehicles, or when upgrading factory plumbing to higher-flow aftermarket components. Compatibility depends on your specific system ports—verify that your fuel regulator, coolant manifold, or gauge cluster uses 1/4 NPT female ports before ordering. Installation requires only a wrench for the swivel nut and a socket or pipe wrench for the NPT end; tightening the female swivel 1–1.5 turns beyond hand-tight ensures a leak-free seal without over-torquing the hose fitting. Always test for leaks under pressure before full operation.