EVIL ENERGY 6AN Male to 3/8" & 5/16" Quick-Disconnect Adapter Pair — 6061-T6 Aluminium, 1500 psi

EVIL ENERGY 6AN male to 3/8" & 5/16" quick-disconnect female fittings are aluminum adapter couplers that convert a 6AN threaded fuel line to snap-on 3/8" or 5/16" spring-lock connectors for EFI and cooler lines.

These two-piece adapters let you join 6AN (9/16-18UNF) fittings with popular spring-lock fuel hose sizes without cutting or custom plumbing. Machined from 6061-T6 aluminum and sealed at a 37° flare, they are designed to work in fuel rails, return lines, transmission cooler feeds and retrofit LS-swap applications. Rated for 1500 psi and usable from -40°F to 176°F, the pair offers a compact, service-friendly link between AN plumbing and factory-style quick-disconnect hoses.

How do these fittings maintain a leak-resistant connection?

The male 6AN end uses a 37° flare sealing angle, which is a standard method to create a metal-to-metal seal under compression. The quick-disconnect female side features a spring-lock mechanism compatible with 3/8" and 5/16" hose IDs so it snaps securely onto OEM-style fuel rails.

• 6AN thread size: 9/16-18UNF for secure AN connections
• 37° flare sealing to prevent seepage at the connection
• Spring-lock female sockets for fast snap-on attachment
• Two size IDs (3/8" and 5/16") for common fuel hose compatibility

Will these adapters handle fuel system pressure and temperature ranges?

Yes — the adapter body and sealing design are specified for typical engine fuel system conditions. The listed working pressure and temperature range indicate suitability for many EFI and transmission cooler uses, though system compatibility and hose condition should always be confirmed before installation.

• Working pressure rating: 1500 psi for high-pressure service
• Temperature range: -40°F to 176°F for hot and cold environments
• Aluminum construction resists corrosion in most automotive settings
• Plastic spring lock provides secure quick-disconnect action

What materials and build quality should I expect from this pair?

The main bodies are machined from 6061-T6 aluminum, offering a good strength-to-weight ratio and machinability for precise flares and threads. The quick-disconnect element uses a molded plastic spring-lock insert optimized for snap-fit performance with standard fuel hoses.

• 6061-T6 aluminum body for durability and light weight
• Plastic spring-lock insert for reliable snap-on engagement
• Precisely cut 9/16-18UNF threads for consistent AN mating
• Pack of two adapters for paired installations or spares

How do I use these adapters in common automotive installations?

They are commonly used to bridge aftermarket AN lines to factory-style quick-disconnect hoses during swaps, fuel-rail upgrades, or cooler feed installations. Installation is typically straightforward: thread the 6AN male into the AN hose or fitting, then snap the female spring-lock onto the mating hose or rail until it audibly locks.

• Fuel rail connections on EFI and LS-swap projects
• Return lines and in-line fuel sensors where quick disconnects are needed
• Transmission cooler or auxiliary fuel cooler feed lines
• Retrofit scenarios converting AN plumbing to OEM-style hoses

Who is this for? These EVIL ENERGY adapters suit mechanics, hobbyists and performance builders who need a compact, reusable link between 6AN fittings and common 3/8" or 5/16" quick-disconnect fuel hoses. They’re practical for anyone performing engine swaps, adding aftermarket fuel components, or repairing systems where preserving factory-style hose ends is preferred. Verify hose inner diameter and system pressure before fitting, and follow fuel-system safety practices during installation.