EVIL ENERGY AN12-to-AN10 Flare Expander Coupler, 2pc Black Anodized 6061-T6, 1500 PSI

EVIL ENERGY's AN12 male to AN10 female flare expander coupler is a machined 6061-T6 aluminum adapter that joins AN12 male fittings to AN10 female flare lines, supplied as a convenient two-piece set.

Use this compact coupler to connect different AN flare sizes without reworking existing lines. It’s built from aircraft-grade 6061-T6 aluminum, finished with a durable black anodize, and designed for sealed 37° AN flare connections. Rated for systems commonly found in fuel delivery, EFI conversions, cooling circuits, and LS swaps, it’s meant to simplify plumbing changes while maintaining pressure integrity across incompatible flare sizes.

How does this coupler handle pressure and temperature in automotive systems?

The adapter is engineered for demanding vehicle environments: it has a maximum working pressure up to 1500 PSI and covers a wide operating temperature span from -65°F to 252°F. Those limits make it suitable for many fuel and coolant applications where reliability under heat and pressure matters. Assembly relies on the standard 37° AN flare sealing geometry for leak-resistant connections when used with proper fittings and hoses.

• Maximum working pressure: 1500 PSI
• Temperature range: -65°F to 252°F
• Sealing style: standard 37° AN flare
• Use with compatible AN flare fittings and correct torque

What are the exact thread and size conversions offered?

This coupler converts between a female AN10 flare and a male AN12 flare, matching standard AN thread dimensions. Specifically, the AN10 female side uses the 7/8-14 UNF thread form, while the AN12 male side follows 11/16-12 UNF. Those thread fits align with common AN plumbing practices, so it mates to industry-standard AN fittings without modification.

• Female side: AN10 — thread 7/8-14 UNF
• Male side: AN12 — thread 11/16-12 UNF
• Intended for AN flare-to-flare connections

What materials and finish protect the adapter from wear and corrosion?

The adapter is CNC-machined from 6061-T6 aluminum, a lightweight alloy widely used for fluid fittings due to its balance of strength and corrosion resistance. A black anodized surface layer adds abrasion resistance, improves longevity in harsh under-hood environments, and provides a low-reflective finish many builders prefer. The construction keeps the part light while maintaining dimensional stability under typical automotive loads.

• Base material: 6061-T6 aluminum alloy
• Protective finish: black anodized coating
• Manufacturing: precision machined for consistent sealing faces

How is this coupler commonly used during installations?

Installers use the coupler to adapt existing lines when upsizing or downsizing AN plumbing—ideal during engine swaps, EFI retrofits, or when replacing components without changing hoses. It keeps work straightforward by avoiding hose re-ends or new bulkhead fittings, as long as the mating flare surfaces and threads are properly prepared. Always inspect sealing faces and use the correct torque to prevent leaks.

• Applications: fuel systems, EFI conversions, cooling lines, LS swaps
• Sold as a 2-pack for spares or multiple connections
• Fits standard AN flare workflows; no special tools beyond common AN wrenches

Who this is for: installers, performance enthusiasts, and professional mechanics who need a reliable, compact adapter to bridge AN12 male fittings to AN10 female flare lines. If you’re performing an engine swap, upgrading fuel plumbing, or maintaining EFI and cooling circuits and want a lightweight, anodized, pressure-rated solution that matches industry thread standards, this two-piece EVIL ENERGY coupler is built to simplify the plumbing task.