AN hose and fittings come in weird sizes like AN6, 8AN, 10, 12 Ect. How does this come into play when you are planning your automotive fuel plumbing project?
This post will be all about breaking down how to determine what is going on with the plumbing on your ride and eliminating some of the confusion between the different styles used in the automotive world vs dash sizes used in other industries.
AN tubing was designed to create a standard that could provide a flexible alternative to hard line tubing for aircraft and military vehicles. AN stands for Army Navy and is measured in AN Sizing. Now when the automotive world decided to adapt these standards over to performance hose applications they didn't get on the same page and it can cause confusion for folks who come from other industries used to standards measured in Dash sizes like hydraulics for example.
Now the fittings are pretty easy to figure out and AN fittings could be measure in DASH sizes. Where every dash number is 1/16 of an inch an AN6 fitting would be equivalent to 6/16" or 3/8" Fitting size. AN8 8/16" or 1/2" for example.
The similarities end with the fittings and the I.D. (inside diameter) of the hose is designed to match up to an equivalent hard line I.D.
In the automotive world hard line tubing is measured using the O.D. of the tube and that is standardized across the industry. Go into any parts store and you can get hard line by telling them what size you need. How this relates to AN flexible performance hoses is where confusion can come into play.
Let's look at AN8 Hose For example, remember from before AN8 equals 1/2 inch. However this does not equate to 1/2 I.D. of the hose. This AN8 performance hose would be equivalent to a 1/2" Hard Line measured on the O.D. of the hard line tubing. This can have implications when you are working on a High Performance install on a fuel system for example where pressure drop can really impact the flow rates needed to deliver what you need for a trouble free install.