Here is a little info about AN fittings.
Divide the size of your AN fitting by 16 and that gives you the fractional size.
For instance a 6an fitting is 3/8 because 2 is the common denominator of 6 and 16.
2 goes into 6 THREE times (over) 2 goes into 16 EIGHT times. Thus 3/8
12an is 3/4 as 4 is the common denominator.
4 goes into 12 THREE times (over) 4 goes into 16 FOUR times. Thus 3/4.
Hope this helps!
