An "AN" fitting is just a standard fitting that has a single flare at 37 degrees. You can get the flare on one side and about anything on the other, such as NPT or straight thread. The number is the size divided by 16, like "6AN" would be 6/16 or 3/8. "8AN" would be 8/16 or 1/2. This is in tubing size, which is measured in the ID (inside diameter). There are many manufacturers of this type of fittings. All of the HiPO dealers sells them (Jegs, Summit, Herberts).
Hope this helps
Steve
