Metric AN fittings

May be a simple problem that I am not realizing the answer for.
For our metric system based members. I have recently acquired a track car that was built in Germany. It has a BMW engine and I imagine all the accessory components are metric fittings (oil coolers, oil filter housings, engine connections, brake fittings). I am based in the US and would like to begin restoration work on hose ends, as many are from the time the car was first constructed. Where is a good place to get AN hose fittings that terminate in metric threads?
I use the term 'AN' possibly incorrectly, perhaps that is not what flexible steel braided lines are called in Europe or other countries (?).
Please advise if I am too regional in my terminology. :oops:


Mesa, "AN" fittings date back to just before WW II. It was a set of military specifications that covered 37 degree flare fittings that were destined for aircraft and military vehicles. The "AN" refers to "Army-Navy" and the specs really didn't cover hoses per se, those were assemblies with their own part numbers.

What you may be thinking of are stainless steel braided hoses that are commonly found on race cars & aircraft. To further muddy up the definition, there are two principal types of stainless braided line, synthetic rubber-lined (mostly used for oil & water lines), and Teflon-lined (mostly used for brake & fuel hoses). Most professional race teams are going away from the nice shiny stainless steel braided hose in favor of more modern lightweight hose such as Aeroquip AQP Startlite Nomex/Kevlar or XRP Kevlar braided hose. These new hoses are much more flexible as well.
Thanks Niel,
The car was built in 94 and I'd rather keep the period look of the braided hoses, blue/red aluminum ends and metric threads without need for adapters. If such a thing currently exists.

I'm thinking one of our European members will have some direction (or education) for me.
It is very hard to understand why and for what use you are sourcing those so strange fittings ?
Even in europe inches fittings are usedon oilcoolers or watever pump and fuel lines ?
So it is better to indicate where you need to replace some fittings ......
Metric system (to me) is only used on european cars on "adaptor fittings "and mostly ( comunly) on the side threaded on engine case or pumps or filters
For example an oil fit could me 24X150 to an dach12 jic hose
bosch fuel pumps are 18x150 on a side and 12x150 on another

Thanks Michel for the education on how things are/were likely done over there. I have not attempted to determine which fittings are metric or SAE or.... yet. Based on your comments that it is possibly both, I will attempt to get a better understanding on what is actually on the car.
If you describe which european car is and where on the parts you need more spec on fittings I can probalbly tell you which metric thread it is ....

Another common "European design" is situated on calipers and brakes stuff ( brands like Italian Brembo , german ATE ) all very small threads instead to be JIC normative they are usually 10x100mm threads ; this is quite dangerous because they are slightly similar but not in fact because JIC adaptors
seems to screw on but they are"loose" and tightening make the thread to be totally destroyed !!!
On contrary a 10x100 adaptor will not fit onto a JIC hole threaded
This is also hapenning for some small diameters oil senders that can be 12x150 or even 12x 125 that are very close to imperial stuff !!!!
all of the female hose end fittings are AN, IE 37deg flare, but the fittings to which they screw onto can be purchased in metric or imperial thread,.
all of the female hose end fittings are AN, IE 37deg flare, but the fittings to which they screw onto can be purchased in metric or imperial thread,.
Clear answer to my vague question.
Thanks John,

So the primary question now is - Where (preferably in the US, but not critical) is a good source for metric AN fittings?


Lifetime Supporter
all of the female hose end fittings are AN, IE 37deg flare, but the fittings to which they screw onto can be purchased in metric or imperial thread,.
Doesn't that mean you are actually just looking for the adapter fittings from 37 degree flare AN to metric, which seemed readily available.

Ken Roberts

You'll be going around in circles unless you show us the exact lines you want to replace. The hoses you want to replace may not even have AN fittings. They could be hydraulically crimped custom length (made up) hoses.
Actually I don't feel a circular pattern ensues.
Julian noted a possible flaw in the communication, but it is my opinion John is saying all AN hoses are the same around the world (or at least on the bottom side of the world), the only difference is what type thread the end fitting terminates in. Although the way John worded it leaves room for clarification. Hopefully John can confirm.

Ken, the hoses I am concerned with are all braided stainless hose with typical AN looking fittings, not crimp fittings.

It has become clear via information gathered here that I need to confirm whether I have metric, SAE or adapters to SAE currently on the car.
All is apparently possible regardless where the car was constructed.

Thanks everyone for the input.


Lifetime Supporter
I did a little digging on some of the European sites I am familiar with and all seem to offer fairly standard AN fittings, which by definition are SAE threads. One question that may also need answering is do you have metric hose sizes or SAE? The BAT Inc. link I posted previously listed metric thread fittings for AN (SAE) hoses on page 4, so they are definitely available, albeit through perhaps limited sources, they do refer to them as being German sourced. Here is a different version metric specific catalog from BAT
what i thought i made clear is the male AN fitting that you as a rule screw into the cooler or pump or what ever can be purchased with both metric an BSP threads on one end and the AN flare on the other to except a hose end,
if you have an item with a metric flared fitting welded on then i think your stuck with OEM parts.


OK got it, thanks for reconfirming your position John.
I appreciate all the input guys, it has been helpful in realizing the possible variables out there.

Thanks again.