EVIL ENERGY AN6 Male Flare to 1/4" NPT Adapter — Black 6061-T6 Aluminium, Straight 4-Pack

This compact straight adapter lets you join a 6AN (9/16-18 UNF) male flare line to a 1/4" NPT female port without welding or custom fabrication. Machined from aircraft-grade 6061-T6 aluminum and finished with a durable black anodized coating, these adapters give a corrosion-resistant, lightweight junction for performance and maintenance tasks. The design uses a 37-degree flare at the AN end and a 60-degree tapered sealing thread at the NPT end, so proper thread sealant is recommended for leak-free service.

How does this adapter seal between AN flare and NPT threads?

The AN side seals by metal-on-metal contact at a 37-degree flare angle, creating a tight shoulder against a mating flare seat. The NPT side uses tapered 60-degree threads that rely on interference and thread sealant to form a pressure-tight joint. Both methods are standard in automotive and industrial plumbing, but require correct installation steps to perform reliably.

• AN side: 37-degree flare seating for a leak-resistant metal-to-metal connection.
• NPT side: 1/4" tapered 60-degree threads (use sealant or PTFE tape).
• Thread spec: 6AN male thread is 9/16-18 UNF for correct compatibility.
• Installation tip: apply compatible thread sealant to NPT threads; avoid sealing the AN flare face.

What materials and finishes are used, and why do they matter?

Each adapter is machined from 6061-T6 aluminum, a common choice for fittings because it combines strength and low weight. The black anodized surface adds scratch and corrosion resistance while giving a consistent appearance across engine bays or external mounts. These properties make the adapter suitable for environments where metal fittings must resist fuel, coolant, or road contaminants.

• Base material: 6061-T6 aluminum for favorable strength-to-weight ratio.
• Coating: black anodized finish for added corrosion resistance and aesthetics.
• Durability: anodizing reduces surface wear and chemical attack risk.
• Weight benefit: lightweight alternative to steel without sacrificing stiffness.

Where and when should I use this AN6-to-1/4" NPT adapter?

This adapter is useful when connecting performance hoses or hard lines to ports designed for NPT fittings. Typical use cases include retrofits, conversions, or repairs on fuel delivery systems, oil or coolant plumbing, and power steering lines. It is not a replacement for specialized high-pressure or safety-critical fittings unless specified by system requirements.

• Common applications: fuel systems, coolant plumbing, power steering, and vacuum lines.
• Use case: converting AN hardline to an NPT-equipped component or sensor port.
• Limitations: ensure pressure ratings and system compatibility before use.
• Maintenance: inspect threads and flare faces during service intervals.

How should I install the fitting to avoid leaks?

Install the AN flare portion by seating the 37-degree flare against a matching female flare seat and tightening to manufacturer torque guidelines. For the NPT side, apply an appropriate thread sealant or PTFE tape to the male threads before threading into the female port; tighten carefully to avoid over-stressing threads. After installation, pressure-test the connection under normal operating conditions to confirm there are no leaks.

• Do not apply sealant to the AN flare seating surface.
• Use PTFE tape or pipe sealant on the NPT threads per product instructions.
• Hand-start threads to avoid cross-threading, then torque to spec.
• Perform a pressure check after assembly for leak verification.

Who is this for: mechanics, fabricators, and DIY tuners who need a reliable AN6-to-NPT transition will find this EVIL ENERGY 4-pack useful for workshops and on-vehicle repairs. It’s suited for people converting fittings or adding sensors and ports that require a 1/4" NPT thread while maintaining factory-style AN connections. If you require certified pressure-rated fittings for critical systems, confirm compatibility with your system specifications before use.