-AN fitting sizes

MoarAWD · Mar 29, 2017

I bought a 2G a while back, and ended up storing it for the summer. Now that it's starting to get warm again, I've been doing what's necessary to get this beast on the road. I've noticed, though, that the -AN fittings on some of the lines are strangely sized, and was wondering if someone could fill me in on the right way to measure these things. I measured the outside of the hose at 0.556 inches. The red fitting needs a 3/4 wrench also. These two measurements lead me to believe that this is -7AN line. Is that correct? I've found a chart online, but none show exactly where to measure, and I've never had experience with these fitting before.

ob1murry · Mar 29, 2017

You don't need to measure the hose. AN sizes are based on 16ths, so if fitting takes a 3/4 wrench, it is 12/16, so it's a 12AN fitting. Something that takes a 1/2 wrench is 8/16, so it is an 8AN fitting, etc..

So unless it takes a 7/16 wrench, it's not a 7AN fitting.

91talonts1 · Mar 29, 2017

No that's not correct. AN numbers are the nominal inside diameter of the fitting. There is no standard on how big the wrench that fits it is. -8an would be 8/16ths or a half inch.
Fragola 12an fittings take a 1 1/8th wrench for example.

MoarAWD · Mar 29, 2017

This is why I'm confused. I read something exactly like what you just posted, and thought, "ok easy peasy." then I find charts like this:

http://autoperformanceengineering.com/html/AN_Thread_Sizes.html

According to that, a -12AN would take a 1-1/16 wrench..... and it's like this all over the Internet where everyone seems to say a different thing.

MoarAWD · Mar 29, 2017

91talonts1 said:
No that's not correct. AN numbers are the nominal inside diameter of the fitting. There is no standard on how big the wrench that fits it is. -8an would be 8/16ths or a half inch.
Fragola 12an fittings take a 1 1/8th wrench for example.

So what's the best way to determine the size of a -AN fitting after it's installed?

91talonts1 · Mar 29, 2017

Those numbers in that chart are thread pitch not wrench sizes.

MoarAWD · Mar 29, 2017

91talonts1 said:
Those numbers in that chart are thread pitch not wrench sizes.

Ah, ok. But looking at that, if I measured 0.556" OD on the hose, I should have a -8 AN line, correct?

twicks69 · Mar 29, 2017

You also need to know that there are several brands that have off sizes for the fittings and they do not fit standardized AN wrenches. You see this with Earl's, Jegs/Summit brand, China Ebay stuff, etc.

You are best off grabbing two adjustable AN wrenches to keep with your regular set of AN wrenches.

MoarAWD · Mar 29, 2017

twicks69 said:
You also need to know that there are several brands that have off sizes for the fittings and they do not fit standardized AN wrenches. You see this with Earl's, Jegs/Summit brand, China Ebay stuff, etc.

You are best off grabbing two adjustable AN wrenches to keep with your regular set of AN wrenches.

Good to know, thanks!

91talonts1 · Mar 29, 2017

Yeah what Tim just said is what I was getting at. There's no standard for outside dimensions among automotive manufacturers. A fragola fitting might not take the same wrench as say an Earl's.

MoarAWD · Mar 29, 2017

I just found this

http://www.dragstuff.com/techarticles/AN-Reference-Chart.html

Which has a chart for hose. According to that, a 35/64 ID (0.55") hose is a -6AN.

Thanks for the info!

ob1murry · Mar 29, 2017

91talonts1 said:
No that's not correct. AN numbers are the nominal inside diameter of the fitting. There is no standard on how big the wrench that fits it is. -8an would be 8/16ths or a half inch.
Fragola 12an fittings take a 1 1/8th wrench for example.

Interesting, I believe you, I've just never had an AN fitting that didn't fit as I said above. You learn something new every day I guess.

1990TSIAWDTALON · Mar 29, 2017

No way in hell a 1/2" wrench would fit a 8AN fitting. My 12AN drain takes that big ass 1 1/8th wrench also. I think my 4AN turbo feed takes either a 1/2" or a 9/16" just for comparing sizes.

91talonts1 · Mar 29, 2017

MoarAWD said:
I just found this

http://www.dragstuff.com/techarticles/AN-Reference-Chart.html

Which has a chart for hose. According to that, a 35/64 ID (0.55") hose is a -6AN.

Thanks for the info!

That chart is a good one I've used it before. Once you've seen the fittings in person a couple times, you can tell the size just by eyeballing them.

twicks69 · Mar 29, 2017

Even on hoses nowadays you cannot just go by the OD of the hose. Even with braided stainless with reinforced rubber internal I have seen several suppliers with OD variations; especially the Ebay junk. Buy quality hose. With PFTE lined hoses they can sometimes have a smaller OD than the rubber version. Same goes for exotic stuff like kevlar, hypalon / PFTE (XRP HS-79), and some of the higher end stuff. I typically stick with BMRS, XRP, Aeroquip and Goodridge as my main stuff.

Bleakley · Mar 30, 2017

That chart IS a good chart.
My experience --> inside diameters ARE almost all dead nuts between the manufacturers I've used (Earl's, XRP, aeroquip, eBay). As they f***ing should be...
Note: transition fittings transition internal too (too much to suit me, so I usually drill them out a little).
Thread sizes are what they should be, PERIOD.

It should go without saying different companies do things differently - so of course OD on braided hoses can vary.

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-AN fitting sizes

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91talonts1

MoarAWD

twicks69

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ob1murry

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