Plumbing up a fuel system in your hotrod and don't want to spend an arm and a leg
for those AN fittings. Instead of running the expensive red or blue fittings you can
go down to your local hydraulic shop and use SAE fittings.
"AN" (Army-Navy) sizes were established by the Aerospace industry.
The AN numbers are equal to the outside diameter, O.D., of the
tubing in 1/16". Since tubing and hoses can have different
wall thicknesses, the size number does not necessarily tell you how large
the inside diameter will be.
Each AN size number has its own standard thread size. For example using the table
below if you needed a fitting for a 6AN then use a 9/16-18 SAE fitting and you should
be all set.