| "AN" (Army Navy) Sizes were established by the aerospace industry. The measurements represent the O.D. (outside diameter) of rigid metal tubes. Basically, dash sizes are the numerators of fractions with a denominator of 16.
EXAMPLE: -6 is equal to 6/16 in. which is equal to 3/8 in. -8 is equal to 8/16 in. which is equal to 1/2 in. In the examples above, a -6 AN fitting would work with a pipe that has a 3/8 in. O.D. A -8 AN fitting would be used with 1/2 in. O.D. pipe. Here's a simple chart, just in case you don't want to do the math.
The most commonly used fittings are adapters. These adapters connect an AN fitting to a pipe thread fitting. Most fuel pumps, regulators, and canister type fuel filters, come with pipe thread inlet/outlet ports. In order to use braided line, the ports need to be changed to a AN type of fitting. This is when a "pipe to AN adapter" is needed. The most popular sizes used in fuel systems are the -6 and the -8 AN, although some high performance fuel pumps and regulators require a -10 AN fitting. |
| Special Thanks To Russell and Hot Rod |
