AN Fittings
"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.
-02 AN is equal to 1/8 in.
-03 AN is equal to 3/16 in.
-04 AN is equal to 1/4 in.
-05 AN is equal to 5/16 in.
-06 AN is equal to 3/8 in.
-08 AN is equal to 1/2 in.
-10 AN is equal to 5/8 in.
-12 AN is equal to 3/4 in.
-14 AN is equal to 7/8 in.
-16 AN is equal to 1 in.
-20 AN is equal to 1 1/4 in.
-24 AN is equal to 1 1/2 in.
-32 AN is equal to 2 in.
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.