Are AN fittings and JIC fittings the same thing?

While they both use a 37° flare and UNF threads, AN fittings are manufactured to a much stricter tolerance (Class 3 threads) to withstand severe vibrations, and are typically made of lightweight Aluminum. JIC fittings use looser Class 2 threads and are usually heavy steel for hydraulics.

Performance Automotive Hardware

AN Flare Fittings Manufacturer

Name: Aluminum AN 37° Flare Fittings (Automotive)
Brand: OM Engineering Works
Availability: InStock

Military-grade AN (Army-Navy) 37° flare fittings engineered to exact aerospace and high-performance automotive standards. CNC machined from premium, lightweight Aluminum 6061-T6 to a strict ±0.01mm tolerance. These reusable, vibration-resistant adapters ensure leak-proof fluid transfer for fuel, oil, and coolant lines. Finished in durable, corrosion-proof anodizing. Manufactured in Mumbai for global export.

MIL-Spec AN Standard

Lightweight Al 6061-T6

Reusable Metal Seal

±0.01mm Machining Precision

Custom Anodized Finishes

High-Vibration Resistance

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3rd Gen Engineering ISO Quality Standards Global B2B Supply

Aluminum AN 37 Flare Fitting Aerospace Automotive

AN Fitting

CNC Threads

Anodized

37° Cone

6061

T-6 Aerospace Aluminum

±0.01

mm Precision Tolerance

37°

MIL-Spec Flare Angle

100%

Reusable Seal

Product Overview

High-Performance AN Flare Adapters

Originally developed for the U.S. Military around WWII, AN (Army-Navy) Fittings are the ultimate standard for high-performance fluid transfer. Because aircraft and race cars cannot tolerate leaks caused by extreme vibration or high RPM stress, the AN standard utilizes a highly precise 37° flare angle combined with stringent Class 3 thread tolerances to create an unbreakable, reusable metal-to-metal seal without the need for unreliable O-rings or thread sealants.

At OM Engineering Works, we manufacture these premium adapters from solid Aluminum 6061-T6 hex bar stock. Utilizing our advanced CNC turning centers, we hold a microscopic ±0.01mm tolerance on the 37° sealing cone and the UNJF threads. This level of precision is mandatory; any surface imperfection on an AN fitting will lead to highly flammable fuel or hot oil leaks under pressure.

Operating from our facility in Mumbai, we supply these lightweight, high-flow fittings to performance automotive brands, motorsport teams, and aftermarket distributors globally. Every fitting is finished with a protective anodized coating, preventing galling of the aluminum threads and protecting against corrosive racing fuels like E85 or methanol.

Key Advantages of Our Aluminum AN Fittings:

Lightweight Performance: Aluminum 6061-T6 offers a massive weight reduction compared to steel or brass, essential for racing and aviation without sacrificing burst pressure strength.
Class 3 Thread Fit: We machine tighter thread tolerances (Class 3A/3B) than standard industrial JIC fittings, ensuring maximum thread engagement and vibration resistance.
Protective Anodizing: Anodizing hardens the outer surface of the aluminum, preventing the threads from cold-welding (galling) upon repeated assembly and disassembly.
Unrestricted Flow: The internal bores are smoothly transitioned, eliminating turbulence and pressure drops in high-flow fuel and coolant systems.

Why Source from OM Engineering Works?

Automated Scalability: Our high-speed CNC infrastructure allows us to manufacture complex AN shapes (straights, 45°, 90°, tees) rapidly and cost-effectively for B2B procurement.
Custom Finishes: While standard black and blue/red anodizing are popular, we offer customized color coding to match your brand's specific OEM requirements.
Material Verification: We provide full Material Test Certificates (MTC) proving the structural integrity of the 6061-T6 alloy used in your batch.

Technical Details

AN Flare Fitting — Specifications

Dimensional & Threading Specs

Fitting Standard	MIL-F-5509 / SAE AS7124 (AN Standard)
Flare Angle	37° Precision Cone (Metal-to-Metal Seal)
Thread Type	UNF / UNJF (Class 3A/3B Tolerances)
Available Dash Sizes	-3AN, -4AN, -6AN, -8AN, -10AN, -12AN, -16AN, -20AN
Machining Tolerance	±0.01mm (Critical for fuel/oil sealing)
Configurations	Straight Adapters, Reducers, Bulkheads, Port Adapters (ORB)
Manufacturing Process	High-Speed CNC Turning, Multi-Axis Milling
Application Range	Fuel, Oil, Coolant, and Air lines in high-performance environments

Material & Surface Specifications

Primary Material	Aluminum 6061-T6 (Solution heat-treated and artificially aged)
Alternative Materials	Aluminum 7075, Stainless Steel 304/316 (On request)
Standard Finish	Type II Sulfuric Anodized (Improves wear and galling resistance)
Color Options	Black, Blue, Red, Silver/Clear (Custom OEM colors available)
Chemical Resistance	Highly resistant to Pump Gas, E85, Methanol, and Synthetic Oils
Operating Temperature	-65°F to +400°F (Depending on fluid transferred)
Weight Reduction	Approx. 65% lighter than equivalent steel JIC fittings
Certifications	Material Test Certificates (MTC) provided with batches

Our Expertise

How We Manufacture Precision AN Adapters

Aerospace-Grade Aluminum Sourcing

We source premium Aluminum 6061-T6 extruded hex and round bars. The "T6" designation is crucial, meaning the metal has been heat-treated for maximum tensile strength and yield strength, preventing the fitting from splitting under extreme torque or line pressure.

High-Precision CNC Turning

The aluminum stock is processed in our highly rigid CNC turning centers. Aluminum cuts quickly, but the challenge lies in the finish. We utilize specialized carbide tooling to turn the 37-degree cone to an ultra-smooth, mirror-like finish, ensuring absolute sealing without O-rings.

Class 3 Thread Generation

Unlike standard industrial JIC fittings (which use looser Class 2 threads), true AN fittings require Class 3A/3B thread tolerances. We CNC cut these fine UNF threads to guarantee maximum engagement, preventing the fitting from loosening under severe engine vibration.

Smooth Flow Internal Machining

For high-performance applications, internal fluid turbulence robs horsepower. We chamfer and smooth all internal bores and transitions to ensure maximum, uninterrupted fluid flow for fuel pumps and oil coolers.

Anodizing & Anti-Galling Treatment

Bare aluminum threads will "gall" or fuse together when tightened. We send all AN fittings through a Type II anodizing process. This electrochemical bath creates a hardened aluminum oxide layer that protects against corrosive race fuels and provides the iconic colorful aesthetic (Black/Blue/Red).

Visual & Digital Inspection

Fittings are inspected under magnification to ensure the 37° sealing face is free of microscopic scratches. Threads are verified using Go/No-Go plug and ring gauges. Approved batches are carefully packed to prevent dings during export shipment.

Machines & Equipment

High-Speed CNC Turning Centers
Traub Single Spindle Automats
Carbide Turning & Threading Tools
Anodizing & Sealing Baths
Multi-Axis Milling (for Port fittings)

Quality Control

Class 3 Thread Plug & Ring Gauges
Optical Profile Projectors (Cone Check)
Digital Calipers (±0.001mm)
Visual Surface Finish Inspection
Material Test Certificates (MTC)

Material Options

Aluminum Grades for Performance

Aluminum 6061-T6 (Standard)

Properties: The undisputed standard for performance automotive fittings. 6061 alloyed with magnesium and silicon offers excellent corrosion resistance and highly predictable machinability. The "T6" temper means it has been solution heat-treated, giving it the yield strength required to handle high torque and line pressure without cracking.

Best For: High-flow fuel systems, oil cooler lines, nitrous oxide systems, and custom automotive plumbing requiring significant weight reduction.

Standards:

UNS A96061 EN AW-6061 AlMg1SiCu

Aluminum 7075-T6 (On Request)

Properties: Alloyed with zinc, 7075 is one of the strongest aluminum alloys available, possessing a tensile strength comparable to many steels while remaining incredibly light. It is more difficult to machine and anodize than 6061, but offers supreme structural strength.

Best For: Extreme pressure aerospace applications, highly stressed suspension linkages, and ultra-high-pressure motorsport pneumatics.

Standards:

UNS A97075 EN AW-7075 AlZn5.5MgCu

Applications

Sectors Utilizing AN Flare Fittings

Performance Automotive

Plumbing high-flow fuel rails, turbo oil feeds, and dry sump oiling systems in drag, drift, and circuit racing cars.

Aerospace & Aviation

Providing lightweight, vibration-proof fluid transfer for experimental aircraft and light aviation fuel systems.

Custom Motorcycles

Aesthetic, leak-proof oil cooler lines and brake line adapters for high-end custom chopper and superbike builds.

Marine Performance

Corrosion-resistant anodized aluminum fittings used in high-speed powerboat fuel and trim tab hydraulic systems.

Product Comparison

Military AN 37° vs Industrial JIC 37°

Feature / Capability	AN 37° Flare (Automotive/Aero)	JIC 37° Flare (Industrial)
Primary Material	Aluminum 6061 (Lightweight)	Carbon Steel or Stainless Steel (Heavy)
Thread Tolerance	Class 3A/3B (Ultra-Tight/Precision)	Class 2A/2B (Standard industrial fit)
Vibration Resistance	Exceptional (Won't loosen in engines)	Good (Suitable for stationary machines)
Visual Identification	Usually Anodized Colors (Black, Blue)	Usually Zinc Plated (Silver or Yellow)
Primary Use Case	Race Fuel, Oil Coolers, Aerospace	Heavy excavators, 10,000 PSI hydraulics

Common Questions

Aluminum AN Fittings — FAQs

AN stands for Army-Navy. It is a U.S. military specification (MIL-F-5509) developed during World War II to standardize plumbing hardware across different branches of the military. AN fittings use a 37-degree flare angle and highly precise Class 3 thread tolerances, making them the gold standard for leak-proof connections in aviation and motorsports today.

They are visually similar and technically interchangeable in an emergency, as both use a 37° flare and the same UNF thread pitch. However, AN fittings are manufactured to a much stricter tolerance (Class 3 threads) to withstand severe aircraft/automotive vibrations, and are typically made of lightweight Aluminum. JIC fittings are industrial grade, manufactured to a looser tolerance (Class 2 threads), and are usually made of heavy steel for high-pressure hydraulics.

In racing and aerospace, reducing weight is critical. Aluminum 6061-T6 offers an incredible strength-to-weight ratio. It is up to 65% lighter than an identical steel fitting, yet the T6 heat treatment gives it the tensile strength necessary to handle high-flow fuel pumps and high-temperature oil lines without bursting or cracking.

No. Absolutely not. The seal on an AN fitting is created entirely by the metal-to-metal contact between the 37° male cone and the female flare. Adding Teflon tape to the straight UNF threads will not help it seal, and a loose piece of tape can easily break off, enter the fuel system, and clog an expensive fuel injector.

Bare aluminum threads have a tendency to "gall" (cold weld to each other) when tightened under pressure. Anodizing hardens the outer surface of the aluminum, preventing thread galling and allowing the fitting to be reused multiple times. It also protects the aluminum from corrosive racing fuels (like E85 or methanol) and provides the iconic colorful finish.

Yes. We manufacture standard and custom AN flare fittings according to customer drawings, dimensions, materials and thread standards.

Yes. Inspection reports and Material Test Certificates (MTC) can be supplied as required for OEM and export orders.

Related Capabilities

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Explore our heavy-duty JIC, NPT, and BSP threaded adapters manufactured from Carbon Steel and SS 316.

Precision Turned Components

Custom CNC turning services for specialized automotive valves, manifold components, and high-precision spacers.

High-Volume Traub Machining

Automated Traub machining for rapidly producing thousands of specialized nuts, adapters, and plugs with repeatable accuracy.

Need High-Volume Aluminum AN Fittings?

Share your dash sizes (-4AN to -20AN), custom color requirements, or CAD designs for a rapid B2B quote. We guarantee ±0.01mm Class 3 thread tolerances and supply verified 6061-T6 with full MTCs. Mumbai-based manufacturing, globally exported to automotive OEMs.

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Contact Info

24/A, Shreenath IND Estate, Navghar Rd, Bhayandar(E), 401105

+91 9324078101

omeprecisions@gmail.com

Mon - Sat: 09:00 AM - 09:00 PM

Our Services

Precision Turned Components Pipe & Tube Fittings Custom Components Rapid Prototyping & Small-Batch Traub Machining Job Work

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3rd Generation Engineering Legacy. Delivering aerospace precision since 1975.

±0.01mm CNC Tolerances

Verified Al 6061-T6 with MTC

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