EVIL ENERGY 6AN Male to 5/8-18 Inverted Flare Adapter 4-Pack — 6061-T6 Aluminum, Black Anodized, 1500 PSI

EVIL ENERGY 6AN male to 5/8 x 18 inverted flare straight adapter is a durable aluminum fitting that converts AN hose connections to 5/8-18 inverted flare threads for fuel and cooler systems.

This four-piece adapter set offers a compact, high-pressure solution when you need to bridge 6AN lines to components with 5/8 x 18 inverted flare ports. Machined from 6061-T6 aluminum and finished with a black anodized coating, each coupler seals with a 37° AN flare to ensure a tight mechanical joint. The adapters are specified for demanding automotive and industrial uses with a rated working pressure and broad temperature tolerance.

How reliable is this adapter under pressure and heat?

These adapters are engineered for high-pressure fluid work and for use across a wide temperature span. The 6061-T6 aluminum core resists deformation while the anodized finish protects against corrosion. The 37° flare sealing geometry provides a positive metal-to-metal seal when installed correctly.

• Working pressure rating: 1500 PSI for typical fuel and coolant line demands.
• Temperature range: -40°F to 250°F for cold starts and elevated operating temperatures.
• Material strength: CNC-machined 6061-T6 aluminum for stiffness and lightweight durability.

What sizes and threads does this adapter convert between?

The adapter converts a 6AN male coupler to a 5/8 x 18 inverted flare female thread. The 6AN male thread specification corresponds to a 9/18-18 UNF designation for compatibility checks with mating AN hardware. These are straight adapters, not swivel fittings, so they keep hose routing fixed.

• AN side: 6AN male with standard 37° flare sealing face.
• Thread side: 5/8 x 18 inverted flare (9/18-18 UNF equivalence).
• Design: straight, non-rotating coupler suitable for permanent or semi-permanent joins.

Where are these adapters typically used and how do they install?

These adapters are widely used in automotive fuel systems, transmission coolers, oil feeds, and aftermarket plumbing that needs an AN-to-inverted-flare transition. Installation is straightforward: verify thread compatibility, hand-start the thread, then tighten to recommended torque to compress the 37° flare for a leak-free connection. Use thread sealant only where indicated — the AN flare provides the primary seal.

• Common applications: fuel lines, cooler connections, oil feeds, and custom plumbing.
• Installation tips: hand-thread first, then torque to proper spec to avoid flare damage.
• Maintenance: inspect fittings periodically for corrosion or loosening, replace if damaged.

Who is this for? This 4-pack from EVIL ENERGY is aimed at mechanics, performance car builders, motorsport fabricators, and DIY enthusiasts who need a reliable, compact adapter to join AN hoses with 5/8 x 18 inverted flare ports. It’s useful for retrofit projects, repairing mismatched plumbing, or adding aftermarket coolers where space and a strong seal are essential. Choose these adapters when you need a high-pressure rated, lightweight solution with proven AN flare sealing geometry.