A Guide to AN Fitting Sizes
AN (Army-Navy) fittings are a type of JIC (Joint Industry Council) fitting commonly used in motorsport, modified cars, and aviation. They’re popular in aftermarket builds, performance vehicles, and even hobby aircraft.
Choosing the right size AN fitting is crucial for a secure and leak-free connection. This guide will help you understand the AN fitting size chart and choose the correct fittings for your needs, covering AN fitting, hose, and tube sizing.
Decoding AN Fitting Sizes
AN fittings are sized in a particular way, and understanding the system is key to making sure you get the right size for your project.
The Basics of AN Sizing
AN sizes are expressed as a number, and each number represents one-sixteenth of an inch. So, if you’re working with AN-8 fittings, that’s 8/16, or one-half inch.
Generally, this number will correspond to the outer diameter (OD) of the tube the fitting is designed to connect to. But because the actual dimensions can vary a little, it’s always a good idea to check a size chart before you buy.
Male vs. Female AN Fittings
The way you measure male and female AN fittings is a little different.
Male AN fittings are measured by the outer diameter of the threaded portion, while female AN fittings are measured by the inner diameter of the threaded portion.
To make sure you get the right fit, it’s best to check a reliable table or diagram.
AN Fitting Dimensions: A Detailed Look
AN fittings come in a variety of sizes, and knowing the dimensions of each is key to getting a secure, leak-free connection. Here’s a closer look at the dimensions for both male and female AN fittings. Keep in mind that using the correct thread size is critical.
Male AN Fitting Dimensions
Here’s a table showing the dimensions for male AN fittings. Note the AN size, thread size, nominal OD tube size, male fitting inner dimension, and the closest NPT (National Pipe Thread) size.
| AN Size | Thread Size | Nominal OD Tube Size | Male Fitting Inner Dimension | Closest NPT Size |
|---|---|---|---|---|
| 4AN | 7/16″-20 | 1/4″ | [Insert Dimension Here] | [Insert NPT Size Here] |
| 6AN | 9/16″-18 | 3/8″ | [Insert Dimension Here] | [Insert NPT Size Here] |
| 8AN | 3/4″-16 | 1/2″ | [Insert Dimension Here] | [Insert NPT Size Here] |
Female AN Fitting Dimensions
Below is a table outlining the female AN fitting dimensions, including AN size and thread size. The thread sizes listed here correspond to the male AN fittings listed above. These thread sizes are typically SAE (Society of Automotive Engineers) threads.
| AN Size | Thread Size |
|---|---|
| 4AN | 7/16″-20 |
| 6AN | 9/16″-18 |
| 8AN | 3/4″-16 |
AN Hose and Tube Sizing
AN, or Army-Navy, sizes are used for hoses and tubes in high-performance fluid transfer systems. Understanding how these sizes relate to actual dimensions is key to selecting the right components.
AN Hose Sizing
AN hose sizes refer to the inner diameter (ID) of the hose. However, it’s not always a direct measurement in inches. The AN size number is a fraction; divide it by 16 to get the approximate ID in inches. For example, an AN -8 hose has an ID of approximately 0.5 inches (8/16 = 0.5).
Keep in mind that different hose types, like braided rubber or PTFE (Teflon), can have slightly different IDs for the same AN size. For instance, an AN -6 braided rubber hose might have an ID of 0.34 inches, while an AN -6 PTFE hose could have an ID of 0.31 inches. Be sure to use the correct hose ends designed for the specific hose type you choose.
AN Tube Sizing
AN tube sizes, on the other hand, refer to the outer diameter (OD) of the tube. Again, divide the AN size number by 16 to get the approximate OD in inches. An AN -4 tube has an OD of about 0.25 inches (4/16 = 0.25).
Wall thickness can vary from manufacturer to manufacturer, so OD is the most important dimension to consider. For instance, an AN -10 tube will always have an OD close to 0.625 inches, regardless of its wall thickness.
Key Takeaways
Understanding AN fitting, hose, and tube sizes is essential for any project involving fluid transfer. Taking accurate measurements and consulting size charts are critical to finding the right fit. Keep in mind that sizing can vary between manufacturers and even between different types of hoses, so it’s always a good idea to double-check the dimensions before you buy anything.
When you’re putting everything together, use adjustable wrenches or specialized AN fitting tools to prevent damage.
Ultimately, selecting the correct fitting for your specific application is what matters most. Choosing the right components will ensure optimal performance, prevent leaks, and keep you safe.