AN fitting, hose and pipe sizes are some of the most common questions and misconceptions about AN systems. AN is measured in inches, where AN1 is theoretically 1/16" and AN8 is 1/2", so AN16 is 1". AN8 is not 10 or 8mm, which is a common misconception. How to measure is also a common misconception when there are different types of AN fittings, hoses, pipes and key clips. All of these have different measurement values. For the sake of clarity, we have divided the information into different categories:
1. AN-fitting dimensions
2. AN-hose dimensions
3. AN-pipe / tube dimensions
4. AN-key grip dimensions
Do you measure outer diameter or inner diameter? Thread inside or outside diameter? We will explain how to perform this operation here!
AN fittings, short for Army-Navy, emerged during the Second World War when there was a need for fittings that were lighter and better tolerated than ordinary hydraulic fittings. AN fittings have become a standard in aftermarket, performance and hobby aviation.
1. AN-fitting dimensions
AN fittings are simply explained as aluminium JIC fittings with higher tolerances. The tube dimensions are measured on the threads.
AN-fitting male (outside diameter)
Below the thread is shown in inch/metric dimensions in the thread/metric outside diameter.
AN4 = 7/16" -20 = ~9,1mm in threads = ~11,8mm OD
AN6 = 9/16" -18 = ~11,6mm in threads = ~14,2mm OD
AN8 = 3/4" -16 = ~16,6mm in threads = ~ 19,0mm OD
AN10 = 7/8" -14 = ~19,5mm in threads = ~22,3mm OD
AN12 = 1-1/16" -12 = ~23,8mm in threads = ~26,9mm OD
AN16 = 1-5/16" -12 = ~30,2mm in threads = ~33,3mm OD
AN20 = 1-5/8" -12 = ~38,2mm in threads = ~41,4mm OD
AN-fitting female (inside diameter)
The thread is shown in inch/metric inside diameter.
AN4 = 7/16" -20 = ~9,9mm ID
AN6 = 9/16" -18 = ~12,9mm ID
AN8 = 3/4" -16 = ~17,5mm ID
AN10 = 7/8" -14 = ~20,6mm ID
AN12 = 1-1/16" -12 = ~24,9mm ID
AN16 = 1-5/16" -12 = ~31,2mm ID
AN20 = 1-5/8" -12 = ~39,1mm ID
AN-hose end inner diameter
An approximate internal dimension of AN hose ends is shown here. Note that the internal dimensions of hose ends and fittings may vary depending on the type, material, manufacturer, etc. Therefore, these internal dimensions should only be used as a guide.
AN4 = ~3,7mm
AN6 = ~6,0mm
AN8 = ~8,6mm
AN10 = ~11,1mm
AN12 = ~14,3mm
AN16 = ~19mm
AN20 = ~25mm
Corresponding AN adapters generally have a 1mm larger internal diameter. If an adapter is reduced to a smaller thread, the inner diameter will also shrink.
2. AN-hose dimensions
AN hose size is measured inside the hose = (hose inside diameter). Depending on the type of hose, the outer diameter of the hose will vary. The type of hose technology has also changed since the Second World War when these connections were introduced, so the actual dimensions of the AN hose may vary. It can also vary from manufacturer to manufacturer. So make sure you use the right hose for your AN hose ends and AN system!
Braided rubber hose dimension
AN4 = 7/32" ~5,4mm
AN5 = 5/16" ~7,9mm
AN6 = 11/32 ~8,7mm
AN8 = 7/16" ~11,1mm
AN10 = 9/16" ~14,2mm
AN12 = 11/16" ~17,4mm
AN16 = 7/8" ~22,2mm
AN20 = 1-1/8" ~28,5mm
Braided PTFE hose dimension
AN4 = 3/16" ~4,8mm
AN6 = 21/64" ~8,1mm
AN8 = 27/64" ~10,7mm
AN10 = 33/64" ~13,0mm
AN12 = 41/64" ~16,3mm
AN16 = 7/8" ~22,2mm
3. AN-pipe / tube dimensions
AN tube size is measured on the outside diameter of the tube. The thickness varies from manufacturer to manufacturer and therefore the internal dimension will vary. But overall, an AN4 tube has ~1.5mm wall thickness and an AN12 tube has ~2.5mm wall thickness.
AN4 = 1/4" pipe OD = ~6,35mm
AN5 = 5/16" pipe OD = ~7,9mm
AN6 = 3/8" pipe OD = ~9,5mm
AN8 = 1/2" pipe OD = ~12,7mm
AN10 = 5/8" pipe OD = ~15,9mm
AN12 = 3/4" pipe OD = ~19,05mm
4. AN-key grip dimensions
The grip on AN fittings is also measured in inches, and due to different measurements standard in different countries, an adjustable socket wrench or inch tools are recommended for assembly to ensure correct engagement. Special tools are available just for AN fittings, but a standard adjustable wrench will work well.
AN3 = 1/2" = ~12,7mm
AN4 = 9/16" = ~14,3mm
AN6 = 11/16" = ~17,48mm
AN8 = 7/8" = ~22,23mm
AN10 = 1" = ~25,4mm
AN12 = 1-1/4" = ~31,75mm
AN16 = 1-1/2" = ~38,1mm
AN20 = 1-13/16" = ~46,0mm
Post time: May-29-2023