The Complete Guide for Automotive and Hydraulic Applications

AN fittings, also known as Army-Navy fittings, were originally designed during World War II to meet the high tolerance demands of military applications. These fittings were initially used in the aeronautical industry but have since become a popular choice for automotive racing and hydraulic systems due to their strength and reliability. This guide will help you understand the benefits of using AN fittings, how to measure and choose the right size, and common applications.

Benefits of Using AN Fittings

• Easy Installation and Removal: AN fittings are designed to be easily installed and removed, making them convenient for various applications.
• High Pressure and Temperature Resistance: These fittings can withstand high pressure and temperature, thanks to their excellent tensile strength.
• Superior Sealing: Unlike traditional hose clamps, AN fittings provide a more secure connection due to their 37-degree flare angle, offering better sealing and reducing the risk of leaks.

Materials and Construction

AN fittings are made from durable materials such as aluminum, which is the most common and provide:

• Corrosion Resistance: Ensures long-term durability, even in harsh conditions.
• Strength: Capable of handling high-pressure environments without failure.
• Longevity: Withstands extreme conditions, making them ideal for performance applications.

How to Choose the Right Sized AN Fitting

Selecting the correct AN fitting size is crucial for ensuring compatibility and optimal performance. The following guide simplifies the process, providing you with step-by-step instructions on how to measure and select the proper AN fitting size.

How to Measure AN Fitting Sizes

To accurately measure AN fittings, you'll need a few essential tools:

• Calipers: For measuring the diameter of hoses and tubes.
• Thread Pitch Gauge: For measuring the threads.
• Ruler or Measuring Tape: For simple measurements, such as lengths.

Steps to Measure AN Fitting Size:

1. Measure the Outer Diameter of the Hose: Use calipers to get an accurate measurement of the hose's outer diameter.
2. Measure the Inner Diameter of the Tube: Measure the tube's inner diameter using the same calipers.
3. Measure the Thread Size: Use a thread pitch gauge to measure the size and pitch of the threads.
4. Determine Thread Pitch: Measure the distance between threads using the pitch gauge.

Understanding AN Fittings Size Chart

AN fitting sizes are represented by dash sizes, which are measured in sixteenths of an inch. For example, an AN-6 fitting corresponds to a hose with an outer diameter of 6/16 inches (or 3/8 inches). This dash size notation makes it easier to determine the correct size for your application.

AN Fittings Size Chart

Common AN Fitting Sizes and Applications

• AN-4 (1/4 inch): Typically used for brake lines and smaller fuel lines. It's ideal for applications where minimal flow is required.
• AN-6 (3/8 inch): Commonly found in fuel lines, power steering systems, and medium-flow applications.
• AN-8 (1/2 inch): Perfect for coolant lines, oil lines, and larger fuel lines, particularly in high-flow scenarios.
• AN-10 (5/8 inch): Frequently used in oil coolers and turbocharger systems, designed to handle high-pressure environments.

Key Takeaways:

• Always Measure Accurately: Use calipers and thread gauges to ensure proper measurements.
• Consult the Size Chart: Refer to our easy-to-use AN fitting size chart to ensure you're selecting the correct fitting for your application.
• Double-Check Compatibility: Ensure the fittings match your hose and system specifications for a secure and leak-free connection.

By following this guide and using the size chart, you can confidently select the right AN fitting for your application, ensuring a tight, secure seal that enhances your system’s performance. Save this guide for future reference and always double-check your measurements before making a purchase to avoid compatibility issues.