AN FITTING SIZES, TYPES, & COLORS

Product Details & Technical Specs

AN Fittings

AN Fittings are aluminum plumbing components and adapters used in the automotive performance and racing industry to connect stainless steel hoses for fuel systems, coolant, air, water, and oil.

AN Fitting Colors

After machining, AN Fittings undergo an anodizing process which prevents galling on the threaded surfaces, adds protection against corrosion and wear, and gives them their color. Traditionally, AN Fittings are produced in a red/blue color combination, which served as a nod to the origin in army and navy applications for many years. We like to think a tad outside of the box — and have been producing fittings in unique finishes for over a decade.

TiAL PURPLE

Our unique and original colorway. Its polished candy purple AN fitting finish is like nothing you've seen before.

J's racing TEAL

We applied our signature polishing and candy anodizing process to produce a glistening teal colorway.

Candy Apple RED

Here it is: our polishing & anodizing process in play to produce a glistening candy red finish.

24k GOLD

When your car needs to look like a million bucks: Our Gold AN Fittings are a must-have.

Piano Key BLACK

No machining or brush marks here, just a deep jet high-gloss piano-key black AN fitting.

MONSTER
Green

Just the radical color you need to tie your latest build together. Check our our lime green AN fittings.

K-Sport
orange

A classic automotive color re-invented in our high-gloss finish.

AN Fitting Sizes

AN fittings come in a variety of standardized sizes based on a long-standing military specification. This specification dictates angle, threading, and the inside and outside diameters of hose the fittings are used in conjunction with.

AN SizeThread SizeEquiv Tube Size (OD)Hose IDMale ID
-3 AN3/8-243/16″0.13″0.12″
-4 AN7/16-201/4″0.22″0.17″
-6 AN9/16-183/8″0.34″0.30″
-8 AN3/4-161/2″0.44″0.39″
-10 AN7/8-145/8″0.56″0.48″
-12 AN1 1/16-123/4″0.69″0.61″
-16 AN1 5/16-121″0.88″0.84″

NPT Sizes

NPT, or national pipe thread, is a technical standard for defining tapered thread series. These fittings seal on the thread taper, as opposed to on the flare surface like AN fittings.

NPT Thread SizeThreads per InchMale Thread O.D.Female Thread I.D.
1/8″2713/32″11/32″
1/4″189/16″15/32″
3/8″1811/16″19/32″
1/2″1427/32″23/32″
3/4″141 1/16″15/16″
1″11 1/21 5/16″1 3/16″
1 1/4″11 1/21 11/16″1 17/32″

AN Fitting Nut Sizes

AN fittings need some simple assembly. Here are the nut wrench sizes. In order to preserve the high-gloss finish, we commend a set of aluminum hose wrenches and vice jaw inserts.

AN SizeAN Side NutHose Side Nut
-3 AN1/2″7/16″
-4 AN9/16″23/32″
-6 AN11/16″7/8″
-8 AN7/8″1 1/32″
-10 AN1″1 7/32″
-12 AN1 1/4″1 7/16″
-16 AN1 1/2″1 3/4″
-20 AN1 13/16″2 5/16″

Hose Finisher / Hex Fitting

These fittings are designed to accept traditional AN hose, but since they don’t rely on compressing the hose into the fitting to create a seal (and instead rely on an internal worm clamp), any hose that fits the following dimensions could be reasonably substituted.

AN SizeTop ID / Hose ODBottom ID / Max Barb Size
-4 AN12.8 (mm)9 (mm)
-6 AN16 (mm)11.9 (mm)
-8 AN17.75 (mm)12.75 (mm)
-10 AN21 (mm)15 (mm)
-12 AN25 (mm)20.4 (mm)
-16 AN30.58 (mm)27.1 (mm)
-20 AN40.8 (mm)35.05 (mm)

AN Hose

AN Hose is specifically designed (and is required) for AN Fittings. Our AN Hose is Stainless-steel braided with a Nylon braided coating. While many brands are not, our Hose is additionally compatible with E85 and Race-fuel applications. 

AN SizeID / toleranceOD / toleranceTypeOperating/Burst
-4 AN5.56 mm (+0.2, -0.1)11.17 mm (+0.2, -0.1)Nylon Covered500/2000 psi
-6 AN8.71 mm (+0.2, -0.1)14.22 mm (+0.2, -0.1)Nylon Covered500/2000 psi
-8 AN11.13 mm (+0.2, -0.1)17.02 mm (+0.2, -0.1)Nylon Covered500/2000 psi
-10 AN14.29 mm (+0.2, -0.1)20.83 mm (+0.2, -0.1)Nylon Covered500/2000 psi
-12 AN17.46 mm (+0.2, -0.1)24.38 mm (+0.2, -0.1)Nylon Covered350/1400 psi
-16 AN22.23 mm (+0.2, -0.1)29.21 mm (+0.2, -0.1)Nylon Covered350/1400 psi
-4 AN5.56 mm (+0.2, -0.1)11.13 mm (+0.2, -0.1)Stainless1000/6000 psi
-6 AN8.73 mm (+0.2, -0.1)13.89 mm (+0.2, -0.1)Stainless1000/6000 psi
-8 AN11.12 mm (+0.2, -0.1)16.28 mm (+0.2, -0.1)Stainless1000/5000 psi
-10 AN14.27 mm (+0.2, -0.1)20.24 mm (+0.2, -0.1)Stainless1000/5000 psi
-12 AN17.47 mm (+0.2, -0.1)23.82 mm (+0.2, -0.1)Stainless1000/3750 psi
-16 AN22.22 mm (+0.2, -0.1)29.36 mm (+0.2, -0.1)Stainless750/2500 psi
-20 AN28.7 mm (+0.2, -0.1)36.49 mm (+0.2, -0.1)Stainless500/2500 psi

Fitting Types

This fitting connects to AN hose on one end, and accepts a male flare fitting (union, junction, ORB, etc.) on the other. The seal is provided by contacting surfaces.

This fitting is the same as it’s straight counterpart; however, it is available in various different angles. (Commonly 45, 90, and 180) 

Male flare fittings or flare unions allow you to reduce size between or connect two female hose fittings together. The seal is provided by contacting surfaces.

ORB fittings are useful for providing a means to connect your fuel rail, fuel tank, radiator, or other ‘bung’ to a female hose fitting. They seal with a rubber O-ring.

Worm clamps, or hose finishers,  are useful for connecting barb fittings or ‘nipples’ to AN hose. The fitting slides over the barb and is tightened to it and the hose with a screwing clamp.

A Quick-Connect adapter is, as the name implies, used to connect to LS and other steel quick-connect barbs.

A push-loc or “push-lock” fitting is essentially a barb fitting and female hose end fitting combined. A hose slips over the barb end and the female AN side accepts a male AN flare fitting. This is an easy-to-assemble fitting,

A barb fitting provides a barb or ‘nipple’ on one end that a hose slides over. The other end typically is a male NPT thread or straight (metric) thread.

A straight bulkhead fitting is used to connect 2 different AN fittings together. Typically, this is used in braking applications to join both sides together. Some Tee fittings are also bulkhead-mountable.

A banjo fitting is a circular fitting that couples with a banjo bolt. It seals with copper washers on either side of the bolt. This allows it to be mounted in any direction. Typically, it has a male AN flare on the other side.

This is the counterpart to a banjo fitting. It is essentially a hollow bolt that pipes fluid (or gas) from a center hole and out to the banjo portion of the fitting. Typically, this is a straight bolt available in various threads.

This fitting is used as a union male flare to metric male. As pictured, in its steel and zinc form, it is used as a 3AN brake fitting and has a flared female recess on the bottom.

Tube nuts are used in conjunction with tube sleeves to adapt hard lines (typically brake lines) to AN fittings. Each Tube Sleeve requires one tube nut to properly secure it. The nut threads into the AN fitting.

Tube sleeves are used in conjunction with tube nuts to adapt hard lines (typically brake lines) to AN fittings. Each Tube Sleeve requires one tube nut to properly secure it. The sleeve slips over the hard line.

As the name implies, a tee fitting is used to connect 3 different AN fittings together. Typically, this is used in braking applications to join both sides together. Some Tee fittings are also bulkhead-mountable.

A 90 degree bulkhead fitting is used to connect 2 different AN fittings together. Typically this is used in braking applications to join both sides together. Some Tee fittings are also bulkhead-mountable.