Not all AN bungs are the same! AN fittings are all the same with regards to thread pitch, OD, seat angle, etc because this is a standard that has been in place since their invention decades ago. If you take a -6 fitting and hose end from any two manufacturers they will screw together as if made by the same machine, because they are the exact same spec. But what about weld bungs or bolt on bungs?

The reality is that these are not always the same, or at least not always to spec. The ID of any AN size is supposed to be standard. The -6 in fact stands for 6/16ths. The numbers refer to the number of 1/16ths of an inch. So a -12 is 12/16, or 3/4. But for some reason the bungs that we use for turbo drains, feeds, fuel tank bungs, and more are not all created equal. They are supposed to have these same ID’s just like the rest of the fittings, hoses, and hose ends, but some cheap ones are not being drilled to the proper size so you need to pay attention when buying them.

If you don’t, you could end up with a much smaller orifice which doesn’t flow nearly as much as the size you have coming into it and that doesn’t make much sense.

Video Description:

This week’s triple T is a short / simple and important one. We will discuss AN fittings and why it’s not always as easy as “if it screws in, that must mean it’s a proper fit!” Come hang out with Doug as he walks you through a big thing to really key in on with ANY AN fitting of whatever type you’re working with on your build.