does any body know how these are measured? i mean i see 4an,6an,8an,12an, im pretty sure there different sizes but im wondering how they are measured because i want to make my own lines for my turbo set up and before i can i need fittings and before that i need to know what size i need. thanks

 

each "an" is a 1/16 of a inch..

so 8an is 1/2" of an inch.

 

http://www.aeromotiveinc.com/tb.php?id=68

 

thanks alot guys